Release 2.0.0

Fix bug with duplicate linked sources being created

Fix issue when multiple linked sources have the same name

Micro-optimizations

Add check to improve performance

Release RC4

Improve error messages

Add non-generic ILinkedSource

Should help catch more errors at compile-time instead of at runtime

Release Candidate

Merge LinkIt.Conventions into LinkIt

Since LinkIt.Conventions is always packaged with LinkIt,
might as well merge them; it makes NuGet generation easier.