[FIXED JENKINS-22822] PeepholePermalink should maintain an in-memory cache of symlinks to avoid disk I/O.

[JENKINS-23151] Need to revert part of 5789f0c7 since codemirror-mode on f:textarea apparently does not work for lazy-load fragments.

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

[FIXED JENKINS-22938] SSH slave connections die after the slave outputs 4MB of stderr, usually during findbugs analysis

Signed-off-by: Oleg Nenashev <o.v.nenashev@gmail.com>