* Check that dependencies are enabled. A disabled optional dependency
  will not prevent a plugin from loading.
* Check versions of dependencies declared by a plugin before loading it.
  If any dependency (even optional) is older than what is required,
  then the plugin isn't loaded.

This should prevent use cases where a plugin is loaded but one of its
dependencies is too old so that :
* its @Extension annotated classes cannot be loaded, causing the full
  Jenkins to blow up with crapload of exceptions which are tedious to
  investigate to understand the root cause.
* NoSuchMethodError and the likes at runtime even though boot has
  completed.

Version check (for setups where version list is manually crafted but yet
works) can be disabled by starting Jenkins with

-Dhudson.PluginWrapper.dependenciesVersionCheck.enabled=true

Minor fixes done while implementing this change :
* Fix version parsing in PluginWrapper.Dependency
* Dynamic plugin load didn't check for disabled flag

Without it version of optional dependencies is set to "X.Y;resolution:=optional" which causes problems when using hudson.util.VersionNumber comparison methods.

[JENKINS-34710] - PluginWrapper should not throw IOException if somebody enables the enabled plugin (#2327)

[JENKINS-34683] - Do not print stack trace if plugin is missing dependencies

Also adds some API restrictions for JENKINS-33803.

This reverts commit fa39668b, reversing
changes made to be9bc0db.

This reverts commit 0846358b, reversing
changes made to 2c9adc99.

Display of shortName of disabled plugin is enough. Fix copy-paste error
in the message for disabled dependencies

And don't fail if no version can be found.

* Check that dependencies are enabled. A disabled optional dependency
  will not prevent a plugin from loading.
* Check versions of dependencies declared by a plugin before loading it.
  If any dependency (even optional) is older than what is required,
  then the plugin isn't loaded.

This should prevent use cases where a plugin is loaded but one of its
dependencies is too old so that :
* its @Extension annotated classes cannot be loaded, causing the full
  Jenkins to blow up with crapload of exceptions which are tedious to
  investigate to understand the root cause.
* NoSuchMethodError and the likes at runtime even though boot has
  completed.

Version check (for setups where version list is manually crafted but yet
works) can be disabled by starting Jenkins with

-Dhudson.PluginWrapper.dependenciesVersionCheck.enabled=true

Minor fixes done while implementing this change :
* Fix version parsing in PluginWrapper.Dependency
* Dynamic plugin load didn't check for disabled flag

Also ... unbundling of plugins from Jenkins core.

Warn users if the pinning is preventing Jenkins from overwriting older versions with bundled versions.

[FIXED JENKINS-12753] Added PluginStrategy.getShortName to avoid actually trying to unpack a plugin before throwing RestartRequiredException.

This reverts commit 2d40b7e7.

This reverts commit b32d0e4f.

to be used by other component to log/resolve configuration issue.

required minimal version

Since sorting of plugins in the update manager is based on displayName
this name should not have a common prefix otherwise it's hard to find
a given plugin name.

Defense against an exception consistently thrown when running functional tests against 1.532.1 (but not 1.540, for whatever reason):
… hudson.PluginWrapper stop
WARNING: Failed to shut down …
java.lang.NullPointerException
	at jenkins.model.Jenkins.lookup(Jenkins.java:3898)
	at hudson.PluginWrapper.getPlugin(PluginWrapper.java:287)
	at hudson.PluginWrapper.stop(PluginWrapper.java:377)
	at hudson.PluginManager.stop(PluginManager.java:650)
	at org.jvnet.hudson.test.TestPluginManager.reallyStop(TestPluginManager.java:129)
	at org.jvnet.hudson.test.TestPluginManager.access$000(TestPluginManager.java:55)
	at org.jvnet.hudson.test.TestPluginManager$1.run(TestPluginManager.java:140)

Normally this is only printed during functional tests or during in-process restart.
In neither case do we really want to see a log message (i.e. two lines of text) for each plugin in the system being stopped.

Added uninstaller that removes *.jpi.

exposed data about installed plugins, installable plugins, update center jobs, etc., to the REST API