[WORK IN PROGRESS] Search Service

Heeeeeeere's the search service! Eventually. This is a work-in-progress PR, meaning I will be adding a lot to it. I do recommend you try to come back and view it occasionally though.

Missing Still:
- [ ] Querying interface in NuGet.Indexing
- [ ] Console app to use NuGet.Indexing to manually edit the index
- [ ] Custom Analyzers/Tokenizers/Shinglizers/Whoosawhatziers for NuGet data (the part that actually matters :P)
- [ ] Runnable Search Service that allows querying the index from a RESTful API (the part you actually use :))
- [ ] Work Service Job to rebuild/update the index
- [ ] Work Service Jobs to monitor the index