Fix documentation typos
Fix error in `ImageBuf::from_fn`. Closes #60
Ignore Cargo.lock

See https://github.com/PistonDevelopers/piston/issues/519
Corrected types of variables, updated Cargo file, removed unused import
Change to new `use foo as bar` syntax
Added travis image
Added .travis.yml
Moved Travis CI image to heading
Add color space conversion methods to DynamicImage
fixed tests

corrected path to test images
Expand 1, 2, 4 bit grayscale images to Grey(8)
Reading of paletted images.
Scale < 8 bit images to full 8 bit.
Added clarifying comment.
Switch to new byte string syntax for chunk name matching.
Add ImageBuf::into_vec
Update Travis CI
Remove path setting
Added benchmark
Added benchmark for a big file.