Removed default Vim semantic trigger for '.'

People find it annoying. It's easy for the user to add this if it's not
the default, but impossible to remove it if it is the default.

Fixes #34
Fix tests
Updating to clang 3.5
Using clang 3.5 clang_includes
Add GoToUsages completer command for CSharp completer
Prevent starting OmniSharp if Omnisharp has already been started
Crude razor support
Add Build command for C# completer
Allow overriding the omnisharp path by instance
Add code issues
Omnisharp request/response logging