Release v2.9.0

Changelog

• CodeMatcher: Update to partially match current upstream codebase
  • Adds some new overloads for matching
• CodeMatcher: Add implicit cast to CodeMatch from OpCode to simplify simple matches
• Harmony: Implement IDisposable interface implicitly
  • Allows writing temporary patches with using syntax
  • Disposing of Harmony will call UnpatchSelf()
• Fix cases where handler block didn't have an explicit end (#46)
• Add HarmonyEmitIL attribute to dump patches as DLL (Documentation)
• HarmonyManipulator: Add new overload for simplified patching
• Updated MonoMod.RuntimeDetour to 21.12.13.1 (changelog)