AngryLawyer/rust-sdl2 — pull request #187 by bbodi (2014-10-08 12:34:24+00:00)
Title: SDL_LockTexture returns the pitch of the locked texture, so rust-sdl2 should so

In my application I need the pitch of the texture after I locked it, so this (or some similar) modification is required to be compatible with the original SDL 2 API.

I use it in the following way:
```rust
let (c_buffer, pitch) = match (screen_texture.lock(None)) {
Ok( (c_buffer, pitch) ) => {
(c_buffer, pitch)
},
Err(e) => fail!(e)
};
```