fix javadoc punctuation for Initializer.after

[JENKINS-59267] Increase ping frequency to prevent timeouts, and make it configurable

Use more common MIT license URL

minor improvements to unit tests

Unbundle Maven Plugin and Subversion Plugin

English: an hpi file

Note that CSRF crumbs aren't really needed anymore for API clients

Remove plugins bundled for promotion

Improved null handling in AbstractProject.<init>

Annotate ProcessTree with @CheckForNull/@Nonnull

Update script-security to 1.65

[JENKINS-59152] - Reduce the default process soft-kill timeout from 2 minutes to 5 seconds

Misc cleanups

[JENKINS-59580] Fix WindowsOSProcess.getEnvironmentVariables returning null

Use type inference instead of specifying it

Fix ProcessTreeKillerTest#doNotKillProcessWithCookie to work on Windows

Spotbugs: changed order for compare instead of negating result 

Spotbugs: Replaced inefficient Number constructor with static valueOf

Trailing whitespace, wrong indentation

Javadoc for ProcessTree#killAll says that "either of the parameter can be null",
but it wasn't true for proc.

[JENKINS-58993] do not allow save() to be called before we have loaded the config

OSProcess.getEnvironmentVariables javadoc clearly states that method will return empty map if obtaining of environment variables failed.