Make the configuration pages localizable
Resolve a few IDE warnings
Remove unnecessary buildServerUrl setting
Use HipChatNotifier#perform instead of HipChatListener
Consolidate plugin configuration

* The settings in the JobProperty has been moved to the Post Build Action
area, to better conform with existing plugins (e.g. IRC Publisher)
* The JobProperty is no longer used for preBuild notifications, instead the
HipChatNotifier is being leveraged now.
* Modified the Jelly files to better conform with conventions, this also
resulted in some code removal in the DescriptorImpl, as now we can leverage
the bindJSON mechanism with structured forms.
Reformat global.jelly
Add notification test to global config page
Define dependencies in dependencyManagement and remove scm/tag
Use consistent variable names & default values
First set of localization work