Specify both Before and After, since Visual Studio 2012 was treating "after spacer margin" as also "after outlining margin"
Add and export a ViewOptionDefinition for controlling visibility of the diff margin
Use the DiffMargin view option to control the visibility of the diff margin (changes to the option for a text view are immediately applied)
Immediately apply changes user makes to the color of the diff margin indicators
Add a new user option to disable the diff margin
Update author to indicate project includes other contributors
Merge branch 'diffmargin-options' of https://github.com/sharwell/Git-Source-Control-Provider