Make sure that change log annotation cannot result into exception

Although javadoc for ChangeLogAnnotator#annotate() states that any exception should be caught in this method and it should return normally, some implementation don't respect it or e.g. in case of missing some dependecy (resulting into NoClassDefFoundError) plugin itself can hardly ensure that no exption is thrown. We should ensure it on the core level.
[JENKINS-16341] Amelioration of memory leak by at least interning some heavily redundant strings.
Merge branch 'master' of github.com:jenkinsci/jenkins
Use request protocol for configured Jenkins url
[JENKINS-16342] Improving responsiveness of asynchPeople when Gravatar plugin is in use.
This change does not necessarily improve total performance, since the avatar is still computed.
But (1) the computation is correctly done in the work thread, not in the HTTP response thread;
(2) the computation is done just once for a given User, which could reduce load when many AJAX checks are done.
Added bug number to the test
Add changelog record for pull #671
Merge remote-tracking branch 'jenkins/master'
Merge pull request #650 from vjuranek/changelog_except

Make sure that change log annotation cannot result into exception
[JENKINS-16341] INSANE testing shows that a RenderOnDemandClosure binding adds about 380k, with or wothout 08efdf5.
Merge branch 'master' of github.com:jenkinsci/jenkins

at least interning some heavily redundant strings."

This reverts commit 08efdf5d3ab962cfd4c4c489266592fe1db7df8e.

Conflicts:

	changelog.html