kripken/emscripten — pull request #1856 by coolwanglu (2013-11-25 20:26:48+00:00)
Title: Implement SDL_LowerBlit

`SDL_LowerBlit` is 'semi-private' according to the documentation.

It is the same as `SDL_UpperBlit` except for no parameter checking. It is required by PDCurses.

I also made a few minor modifications about `scrollHeight`