Merge pull request #840 from danbarua/master

Add CONTRIBUTING.md
Added new Reference Attribute for Load/Save references in OrmLite
Merge branch 'master' of https://github.com/ServiceStack/ServiceStack
update latest OrmLite, Text dlls
Update code-base to use OrmLite's new APIs
Update stale OrmLite.Sqlite dlls
check-in latest SS.Redis dll
Make user-facing UserAuthRepository's implement IUserAuthRepository +remove where T constraints
Change RegisterService to fallback to IAuthRepository if IUserAuthRepository<TUserAuth> doesn't exist
Rename UserAuthProvider to UserAuthDetails and fix broken AuthUser tests
Enable IdUtils to work with Interfaces
Default HostContext.ResolveService to use HttpContext.Current
Remove hidden complexity of explicit interfaces. Reduce IUserAuthRepository interfaces required
Ensure you save Against TUserAuth table and not IUserAuth
Add v3-fixes AuthTests fix from lts-tyson
Add AutoHandleOptionRequests on CorsFeature
Merge Auth and Caching Providers in SS.Contrib into SS main repo + refactor to match latest SS Auth
rename UserAuthProvider to UserAuthDetails
Update NuGet repositories.config
Rename DigestHA1Hash to DigestHa1Hash to keep consistent Pascal naming of acronyms