debian: Fill in gecos field for jenkins user

Otherwise when Jenkins runs git, git will complain that the identity is
not set up correctly and will fail.
Keep consistence in pendings when exception is thrown during method pop()
[JENKINS-3107] Expand an Advanced section if some fields are already customized.
Initial implementation handles only text fields, not e.g. checkboxes.
[JENKINS-3107] Rather than preëxpanding the Advanced area, just show an icon.
[JENKINS-3107] IE 9 fix.
[JENKINS-3107] Icon looks better before button rather than after, for reasons of alignment with the rest of the form.
Using mojo extra-enforcer-rules enforceBytecodeVersion.

This rule enforces a bytecode version in dependencies.
This would prevent cases like JENKINS-8914 where someone had
introduced a dependency compiled with JDK1.6 at a time where
Jenkins was still on 1.5.

With 1.7 already here and 1.8 coming, this should help no to do that
again.
Using a property to share target jdk version with enforcer rule.
Add test if jobs do not stuck in pendings
Fixed confirmPOST JS utility not working with CSRF protection enabled.
[JENKINS-14362] Switch to jzlib for GZIP streaming.
[FIXED JENKINS-17276]

Noting the fix.
[JENKINS-18282] Introduce get-node CLI command
[JENKINS-18282] Introduce update-node CLI command
[JENKINS-18282] Introduce create-node CLI command
Introduce CLICommandInvoker for testing purposes
[FIXED JENKINS-18282] Optionally override name from XML in create-node CLI command
Merge commit '9d8ee80' into rc
back to 1.513
Stapler ≥2.11 to use