v0.10.0-beta.1

What's Changed

• Dropped 'lua lifetime (subtypes now store a weak reference to Lua)
• Removed (experimental) owned types
• Make Lua types truly Send and Sync (when enabling send feature flag)
• Removed UserData impl for Rc/Arc types ("any" userdata functions can be used instead)
• Lua::replace_registry_value takes &mut RegistryKey
• Lua::scope temporary disabled (will be re-added in the next release)