Update relative path calculation to properly account for case-insensitive file systems
Update blob lookup to properly account for case-insensitive file systems
Merge pull request #58 from sharwell/case-insensitivity

Case insensitivity
Add a VSPackage to the project (required for menu commands and options pages)
Define toolbar commands for the Git Diff Margin actions
Use IVsToolbarTrayHost to provide the toolbar functionality