Move final nested class Convertor to RubyToCConvertor
Extract class ClosureToPointerConvertor
Do not include development tools in the bundle when running on Travis CI
Separate creation of InOutPointer from setting its value
Unify argument pointer creation
Use RubyToCConvertor in ArgumentBuilder
Unify ingoing argument conversion code
Use CToRubyConvertor for outgoing argument conversion
Remove unused methods from BaseArgumentBuilder
Avoid re-calculating getter method name on each iteration
Fix some code smells
Clean up BaseArgumentBuilder
Use BaseArgumentBuilder#new_variable always
Fix tests to deal with changed argument names
Clean up test setup to avoid duplication
Add skip guards for builder tests
Remove unused test helper method
Use separate setup for each vfunc integration test