Removed some duplicate code in mainWindow

- Create a new function openRepository which opens the repo and returns a bool
if opening fails

- Moved the propogate repo info series of calls to its own function
removing duplication.
Remove commit.cpp/.h

Commented out files that are now not required.
Added ability to quickly navigate to tags

Quick navigation from the drop down tags menu to the commit that was tagger
now works again.
Remove cruft
Moved function to find commit index

Like operations should be grouped with like operations.
BUG: Line up staging and working directory graph entries with other entries
Remove debug
Break up the off click menu into more manageable pieces

With some up coming changes moving these pieces into their own
functions is going to make things easier.