WiP: Add support for triggering jobs on the change-merged event

Added a new event ChangeMerged to encapsulate the change-merged Gerrit
event, and added a new class GerritTriggeredEvent from which all event
classes are now derived.

Existing code is refactored to use GerritTriggeredEvent instead of
PatchsetCreated.

Since not all Gerrit events can be scored, extended the GerritEvent
interface to include a new method isScorable.
Add triggering on comment-added.

Add new CommentAdded event class.
Add config option to trigger on comment-added event with a specific vote
category and value, ie, trigger on CRVW 2 (approved code review).
Fix problem with config screen not correctly displaying selected trigger.
Change TriggerContextConverter to use GerritTriggerEvent superclass
rather than PatchsetCreated event.
Update build-config dependency versions.

Update to 1.2.5-SNAPSHOT.

Fixes https://issues.jenkins-ci.org/browse/JENKINS-12824
Use event as key in BuildMemory.

Removes PatchSetKey class which was used as the key to a build memory.
Replaces it with simply using the event as they key (a custom comparator
is used to ensure that the java.lang.Object hashcode is used as the key).

Also add the hash of the event as an extra build parameter.  This allows
otherwise duplicate builds to be scheduled.

Together, these changes ensure that every Gerrit event triggers a full
complement of the jobs that are listening for it, all of them are
scheduled, and all of them report back to Gerrit as a unit, even if
multiple events of the same type and for the same change arrive.
Add uploader field back to PatchsetCreated.

Add GERRIT_EVENT_ACCOUNT* parameters to build, which represent the
account info of the person who uploaded/authored/abandoned, etc.,
whatever caused the event.
Fix copyright/author notice on CommentAdded
Add Approval DTO.

CommentAdded has Approvals now, which are checked in GerritTrigger before
scheduling builds triggered by CommentAdded events.
Add findUploader back.

Restore behavior expected by test suite with regard to patchset.uploader
or event uploader being null.
Checkstyle fixes
Remove readObject.

We don't need to fix up the attributes after deserialization, we just
need the old field marked transient and the deserializer won't complain.
Fix comment added implementation.

Typos from refactoring.
Add RefUpdate event type.

Many parts of the code assume that an event has a non-null change attributes.
Ref-updated events don't so add checks to see if change is null throughout the plugin.
Merge branch 'trigger-on-comment-added-2' into trigger-on-ref-updated-2

Conflicts:
	gerrit-events/src/main/java/com/sonyericsson/hudson/plugins/gerrit/gerritevents/dto/GerritEventKeys.java
	gerrithudsontrigger/src/main/java/com/sonyericsson/hudson/plugins/gerrit/trigger/gerritnotifier/model/BuildMemory.java
	gerrithudsontrigger/src/main/java/com/sonyericsson/hudson/plugins/gerrit/trigger/hudsontrigger/GerritTrigger.java
	gerrithudsontrigger/src/main/java/com/sonyericsson/hudson/plugins/gerrit/trigger/hudsontrigger/GerritTriggerParameters.java
	gerrithudsontrigger/src/test/java/com/sonyericsson/hudson/plugins/gerrit/trigger/hudsontrigger/GerritTriggerTest.java
	gerrithudsontrigger/src/test/java/com/sonyericsson/hudson/plugins/gerrit/trigger/mock/DuplicatesUtil.java
Style fixes.
Add JGit repository

Now repo.jenkins-ci.org and central do not have the past JGit packages.
git-plugin needs it.

So add JGit official repository until git-plugin supports the latest one.
Add help resource for "Build current patches only"
Improve Japanese translation

Fix difference between page content and help one.
Correct English in GerritAdministrativeMonitor properties
Correct Gerrit version dependency for "Trigger on files" plugin

The "Trigger on files" plugin requires Gerrit version 2.3, not 2.2.3.
Minor English correction.