Detect HEAD and place it accordingly with special color

* on the branch ref if the branch is checkouted
* on the commit if detached head
Display different style for types of references

Note: we can't be sure that a ref is a remote,
so looking for ref containing "/" which should
be sufficient for a demo repository...
Add open folder button
Accept a repository path as a command line parameter

Let GitViz be added to the "Send to" contextual menu
%APPDATA%\Microsoft\Windows\SendTo
Display the name of the repository in the Window title bar
Merge branch 'improvements' of https://github.com/pmiossec/GitViz into pmiossec-improvements
add .gitattributes and a minor cleanup of PR #4
Merge branch 'pmiossec-improvements'