changes to EmbeddableDocumentStore:
added UseEmbeddedHttpServer, httpServer dataMembers
added function SetStudioConfigToAllowSingleDb
added httpServer initiation and call to SetStudioConfigToAllowSingleDb in case no URL was recieved and UseEmbeddedHttpServer was true

other changes:
added RegisterListener to IDocumentStore interface, as a result updating the documentStore and the embeddedDocumentStore
Fixing build & some tests
Fixing tests
Fixing the release of an old pager state in Win32MemoryMapPager and FilePager
Fixing Voron's full backup test by creating restore paths if they don't exist
Fixing test by changing the exception messages
Merge branch 'voron-pager-release-fixes' of https://github.com/arekais/ravendb
More passing tests
Be more protective of registering listeners late
Fixing listeners wiring