Improve dot vs colon method invocations - #109

This implements #108, as well as a couple other fixes:

• Adds a !DotMethod decorator, which can be used on classes, interfaces, and methods to indicate they should be called using dot syntax (e.g. instance.method() as opposed to instance:method())
• Fixes static methods, which are now always called using dot syntax
• Adds a test that ensures that the appropriate syntax is used with classes, interfaces, instance methods, static methods, and the decorator.