Introduce Native.simple; port some overrides to Override.simple
Replace Override.simple with Override.create, that supports returning long values and lets functions use the context. Fixes #379.
Always return booleans for functions that should return booleans
Transform values returned by equals and equalsIgnoreCase to booleans
Merge pull request #441 from marco-c/native_simple_override_simple

Replace Override.simple with Override.create