[gitk] [PATCH] 0/2 Merging master into dev

I've merged the current changes for gitk master onto the dev branch and fixed some conflicts and then modified the default colour assignments for windows to use the system colours so that it will pick up the stock colours defined via the windows property pages.

However, I'm not too certain how to post such a merge commit. Usually I do 'git format-patch -M' but in this case that emits all the commits that were merged. It looks like 'git show -p' is producing a merge patch so I am posting that for 1/2 and a normal patch for 2/2. If there is better way let me know and I will redo.

Note: these patches are for the gitk dev branch.

Hopefully this themed tk version is suitable for merging up to master soon as this will significantly improve the look of the application in msysGit.