Search Service

Search Service + Small testing app, since the Work Service changes depend on this being checked in and built.

Still a work in progress, but remaining work is dependent on this code being merged to master. Pending work:
- [x] Port over IndexUpdatesTask
- [x] Set up TeamCity build to produce and push NuGet.Indexing.nupkg
- [x] Port SearchApp over to Search Service project
- [x] Write work service tasks to maintain index (simple wrappers around the tasks used by IndexMaintanance) - This will happen in the Work Service Repo