Cleanup the R# V8 support

- There was an inconsistency with how ReSharper was cased in type names
and namespaces. I decided to go with ReSharper.  This is how the
JetBrains team spells it on their site.
- Changed the implementation of ReSharperExternalEditAdapter a bit to
enable unit testing
- A few nit picky stile issues (mostly sealing of types)