Add GetLongpollDelta method
Add overloads which include CancellationToken

This should be a non-breaking change; I have added overloads, rather
than using optional parameters.
Use correct URL for GetLongpollDelta
Fix GetDelta response parsing
Improve error handling for GetDelta and GetLongpollDelta
Fix GetDelta and GetLongpollDelta authentication
Expose Timeout property on Client
Add overload to specify parentRev when uploading
Project clean up, nuget package restore (VS2013)
Merge branch 'cancellation' of https://github.com/tgjones/DropNetRT into tgjones-cancellation
v1.3 - PR #13
Merge branch 'tgjones-cancellation'