- Fix Rect#[]=. return statement should be outside of case statement, should    return value instead of index to be consistent with Array. - Add RDoc-style documentary comments.
- Fix Rect#[]=. return statement should be outside of case statement, should 
  return value instead of index to be consistent with Array.
- Add RDoc-style documentary comments.


singpolyma/rubygame,rubygame/rubygame,firstval/rubygame,singpolyma/rubygame,Dami-coding/rubygame