Updated to latest Rust
Merge pull request #48 from ozkriff/master

Updated to latest Rust
Updated to latest Rust: ToStr -> fmt::Show
Merge pull request #49 from ozkriff/master

Updated to latest Rust: ToStr -> fmt::Show
Updated to latest Rust: Implemented Show for Mat{2,3,4}
Merge pull request #50 from ozkriff/master

Updated to latest Rust: Implemented Show for Mat{2,3,4}