Add interface and required entities for Commit Comments.
Implement RepositoryCommentsClient
Add Repository Comments stuff to additional assemblies
Add IObservableRepositoryCommentsClient as well as an implementation
Add tests for RepositoryCommentsClient
Merge remote-tracking branch 'origin/master' into 332-repo-comments-api
Updated comments
Extension method for IHttpClient

To not require cancellation token
Merge remote-tracking branch 'origin/master' into 332-repo-comments-api
Run FixProjects
Merge branch '332-repo-comments-api' of https://github.com/wfroese/octokit.net into wfroese-332-repo-comments-api

Conflicts:
	Octokit/Octokit.csproj
Merge pull request #413 from octokit/wfroese-332-repo-comments-api

Wfroese 332 repo comments api