[JENKINS-27624][JENKINS-42709] Bump Jenkins baseline to Java 8 minimum

[JENKINS-43320] Improve JNLP configuration Spanish translations

Making interrupt of `build -s` work in `-http` mode.
Does not solve `ReadPendingException`s.

Using kill -QUIT to try to diagnose client hangs observed on ci.jenkins.io but not locally reproducible.

java.nio.file.FileSystemException: …\.ssh\known_hosts: Incorrect function.
        at sun.nio.fs.WindowsException.translateToIOException(WindowsException.java:86)
        at sun.nio.fs.WindowsException.rethrowAsIOException(WindowsException.java:90)
        at sun.nio.fs.WindowsAclFileAttributeView.getFileSecurity(WindowsAclFileAttributeView.java:88)
        at sun.nio.fs.WindowsAclFileAttributeView.getOwner(WindowsAclFileAttributeView.java:121)
        at sun.nio.fs.FileOwnerAttributeViewImpl.getOwner(FileOwnerAttributeViewImpl.java:91)
        at java.nio.file.Files.getOwner(Files.java:2079)
        at org.apache.sshd.common.util.io.IoUtils.getFileOwner(IoUtils.java:272)
        at org.apache.sshd.common.util.io.ModifiableFileWatcher.validateStrictConfigFilePermissions(ModifiableFileWatcher.java:240)
        at org.apache.sshd.client.keyverifier.DefaultKnownHostsServerKeyVerifier.reloadKnownHosts(DefaultKnownHostsServerKeyVerifier.java:79)
        at org.apache.sshd.client.keyverifier.KnownHostsServerKeyVerifier.verifyServerKey(KnownHostsServerKeyVerifier.java:161)
        at …
Interactive testing of known_hosts on XP works as expected.

[JENKINS-36720] - Cleanup of SOME medium FindBugs issues

Obsolete with Java 8. Permanent generation was removed.

[JENKINS-34670] Add support for a new full screen layout

[JENKINS-42744] - Update WinSW to 2.0.3 and Windows Agent installer t0 1.8

This PR updates WinSW to 2.0.3 in order to fix [JENKINS-42744](https://issues.jenkins-ci.org/browse/JENKINS-42744), which is reported as a critical regression in Jenkins 2.50.

Changelog: https://github.com/kohsuke/winsw/blob/master/CHANGELOG.md#203

Full diff: https://github.com/kohsuke/winsw/compare/winsw-2.0.2...winsw-2.0.3

And suppress associated workaround

[JENKINS-42934] Avoid using new FileInputStream / new FileOutputStream

Remove invalid CSS rule

Inline the method to use concrete subtypes of AbstractBuild to remove ambiguity

```
[INFO] Jenkins war ........................................ SUCCESS [04:19 min]
[INFO] Tests for Jenkins core ............................. FAILURE [ 18.740 s]
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 06:01 min
[INFO] Finished at: 2017-03-29T23:07:16+02:00
[INFO] Final Memory: 92M/504M
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.0:testCompile (default-testCompile) on project test: Compilation failure
[ERROR] /home/tiste/dev/JENKINS/jenkins/test/src/test/java/hudson/model/GetEnvironmentOutsideBuildTest.java:[89,30] error: no suitable method found for buildAndAssertSuccess(AbstractProject)
[ERROR] -> [Help 1]
[ERROR]
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR]
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/MojoFailureException
[ERROR]
[ERROR] After correcting the problems, you can resume the build with the command
[ERROR]   mvn <goals> -rf :test
```

Probably a bit ugly, but well for a test it should be acceptable.

```
[ERROR] Failed to execute goal com.infradna.tool:bridge-method-injector:1.13:process (default) on project jenkins-core: Failed to process @WithBridgeMethods: Failed to process /home/tiste/dev/tmp/2017-03-29T23h05m22+0200-jenkins-core/jenkins/jenkins/core/target/classes/hudson/model/AbstractItem.class: IllegalArgumentException -> [Help 1]
org.apache.maven.lifecycle.LifecycleExecutionException: Failed to execute goal com.infradna.tool:bridge-method-injector:1.13:process (default) on project jenkins-core: Failed to process @WithBridgeMethods
        at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:212)
        at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:153)
        at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:145)
        at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:116)
        at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:80)
        at org.apache.maven.lifecycle.internal.builder.singlethreaded.SingleThreadedBuilder.build(SingleThreadedBuilder.java:51)
        at org.apache.maven.lifecycle.internal.LifecycleStarter.execute(LifecycleStarter.java:128)
        at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:307)
        at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:193)
        at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:106)
        at org.apache.maven.cli.MavenCli.execute(MavenCli.java:863)
        at org.apache.maven.cli.MavenCli.doMain(MavenCli.java:288)
        at org.apache.maven.cli.MavenCli.main(MavenCli.java:199)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:498)
        at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Launcher.java:289)
        at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:229)
        at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:415)
        at org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:356)
Caused by: org.apache.maven.plugin.MojoExecutionException: Failed to process @WithBridgeMethods
        at com.infradna.tool.bridge_method_injector.ProcessMojo.execute(ProcessMojo.java:68)
        at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:134)
        at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:207)
        ... 20 more
Caused by: java.io.IOException: Failed to process /home/tiste/dev/tmp/2017-03-29T23h05m22+0200-jenkins-core/jenkins/jenkins/core/target/classes/hudson/model/AbstractItem.class
        at com.infradna.tool.bridge_method_injector.MethodInjector.handle(MethodInjector.java:106)
        at com.infradna.tool.bridge_method_injector.ProcessMojo.execute(ProcessMojo.java:65)
        ... 22 more
Caused by: java.lang.IllegalArgumentException
        at org.objectweb.asm.ClassReader.<init>(ClassReader.java:170)
        at org.objectweb.asm.ClassReader.<init>(ClassReader.java:153)
        at org.objectweb.asm.ClassReader.<init>(ClassReader.java:424)
        at com.infradna.tool.bridge_method_injector.MethodInjector.handle(MethodInjector.java:74)
        ... 23 more
[ERROR]

```

[JENKINS-42590] : remove text mentioning getDisplayName==null

[FIXED JENKINS-33595] Picks up https://github.com/jenkinsci/sshd-module/pull/11
to turn off SSHD by default, but expose it to tests which wish to enable it.

[JENKINS-42969] UnsupportedOperationException from Computer.addAction

Update German translation