Merge pull request #11 from bvssvni/master

Upgraded Rust-Empty
Add a method for loading a section of an image

Usefull when dealing with large images
Merge pull request #12 from ccgn/master

Add a method for loading a section of an image
Implement a rudimentary image type
Merge pull request #13 from ccgn/master

Implement a rudimentary image type
Reexported colortype enum variants