Plugin v.1.2.1

Changelog:

MAJOR:

• In the Commit Log a branch can now be created for any given commit (with that commit as the source/origin of the branch)
• When pushing a newly created local branch with several defined repositories the plugin now shows a dialog where the remote, to which the branch should be pushed, can be selected by the user

MINOR:

• The plugin description now has a reference to the releases page in github that can be used as a changelog
• The error that is displayed when trying to pull while on a branch with no remote-tracked branch is now displayed as notification instead of an error. This makes it more obvious that the user has to do something
  and the plugin didn't fail for no reason

BUGFIXES:

• The Observables of the actions of the popup menu are now discarded properly
• Everywhere a branch is used, the full name of the branch is used if possible. If only the simple name is passed, the plugin tries to determine the full name before asking JGit to resolve the branch
  This fixes a problem where a tag can be returned instead of a branch if that tag has the same name as the branch
• Files that were selected prior to pressing "commit" are now automatically selected again at the start of the commit dialog. The automatic expansion of the root node also works again
• Pushing a newly created local branch now properly establishes a tracking relationship between the local branch and the remote branch that will be created by the push