Minor UI enhancements

Hi there.
I've being using GitExtensions for ages, and now I think it's time I start contributing.
I aim to add a feature for applying patches from GitHub's pull requests, and hence I'm studying GitExtensions code.
In the meanwhile, I started fixing some little little aesthetic things in GitExtensions's UI.
I hope they could be useful.

I removed the white glow around the IconCommit in FormBrowse
I added a little padding in the FormBrowse Commit info.

Cheers