Merge branch 'mz/pushui'

Merge branch 'mz/pushui'

* mz/pushui: (31 commits)
  Push GUI
  Add PushOperation to plugin
  Universal GUI for specifications edition: RefSpecPanel and related
  Provide a checkbox component for embedding in a table.
  Add few EPL Eclipse icons
  Make Clone's SourceBranchPage more user-friendly
  Create ListRemoteOperation for listing remote repo branches
  Clone wizard: force dir to suggested path only if repo selection change
  Allow selecting empty dir in clone wizard
  Set FileDialog selection appropriately in clone wizard
  Add canCreateSubdir() heuristic in CloneDestinationPage
  Move clone logic away from GitCloneWizard to CloneOperation
  Clone wizard and related: refactor, clean-up, fixes or improvements
  Refactor/rewrite CloneSourcePage to universal RepositorySelectionPage
  Fix typo in uitext.properties message
  Remove debug/test console output from GitIndex
  Add simple abbreviate() method to ObjectId
  Add setFetchRefSpecs and setPushRefSpecs to RemoteConfig
  Add getAllRemoteConfigs() to RemoteConfig
  Add another RemoteRefUpdate constructor, useful for 2-stage push
  ...