Adding go to implementation for all projects.
Merge remote-tracking branch 'upstream/master'
GoToImplementations: tests for - single project and multiple files - multiple projects
GoToImplementations: renaming tests
GoToImplementations: tests for member implementations
Merge pull request #153 from bodicsek/master

Find implementations in all projects
add overirde abstract method support
Merge branch 'master' of https://github.com/OmniSharp/omnisharp-server