Added support for bare repositories
Fixed test that were not compiling.
Added better handling of notifypropertychanged
Added Checkbox to enable visualization of unreachable
Added logic to retrieve the subject of commits
fixed test and parse logic for commit without messages
Added visualization of subject of the commit

Visualization is conditional, to avoid messing up all the graph.
Added the ability to choose the number of commits to show

Tried on a local repository with thousands of commit converted from a Svn repositories with git-svn, a repo with big binary files and really big on disk. Even asking for 1000 commits works with decent speed.
.editorconfig

See http://visualstudiogallery.msdn.microsoft.com/c8bccfe2-650c-4b42-bc5c-845e21f96328
and http://editorconfig.org/
Detect HEAD and place it accordingly with special color

* on the branch ref if the branch is checkouted
* on the commit if detached gead