Switched to NuGet for dependencies and minor test updates.

- Switched to NuGet for managing dependencies instead of having the DLLs
in the reference folder.
- CoreCommunicationTests: Changed expected error message, "when" was
switched to "while"
- IntegrationTests - added a default timeout variable used by
JsonSearch. Set to 5 mins as there seems to be a bigger delay in when
loggly receives the message and it shows up on indexes.  Also switched
from the static "csharptests" to pulling the value in from the config
file.
- Updated the .nuspec to 2.2 and the new dependencies.