update for newer rust: use libc crate instead of std::libc
Add RWops struct implementation
fix #38, use close_on_drop option in RWops
Merge pull request #70 from andelf/add-rwops-struct

Implement SDL_RWops in Rust as sdl2::rwops::RWops
make RWops compatible to i686 platform; also add more patterns to .gitignore.
Merge pull request #1 from lifthrasiir/i686-compat-rwops

make RWops compatible to i686 platform; also add more patterns to .gitig...
README: Add reference link to rust-sdl2_mixer
Merge pull request #72 from lifthrasiir/i686-compat-rwops

Make `RWops` compatible to i686 platform; Also add more patterns to .gitignore.
Merge pull request #74 from andelf/add-ref-link-to-rust-sdl2_mixer

README: Add reference link to rust-sdl2_mixer
Merge remote-tracking branch 'upstream/master'
add a workable SDL_audio implementation
fix unhandled error in calling RWops::from_file
fix return type error
sdl_audio: implement AudioCVT
add SDL_version APIs
Merge pull request #75 from andelf/add-sdl-audio-support

Add sdl audio support.
render.rs: change bool return type to Result
add Renderer::read_pixels, Texture::lock, Texture::unlock.
Merge pull request #77 from andelf/refactor-texture-and-pixelformat

Implement Renderer::read_pixels, Texture::lock, Texture::unlock.
add reference link to rust-sdl2_gfx