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.
Merge pull request #73 from cmr/master

Add ImageBuf::into_vec
Update Travis CI
Merge pull request #71 from nwin/support_nbpp

Support pngs with < 8 bit per pixel
Remove path setting
Merge branch 'pr/74'
Added benchmark
Added benchmark for a big file.
Merge pull request #75 from nwin/master

Add benchmark
Extended image::IoError to hold io::IoError.
Merge pull request #76 from nwin/master

Extended image::IoError to hold io::IoError.
Provide better error messages for unsupported features.
Merge pull request #77 from nwin/master

Provide better error messages for unsupported features.
Include all color modes into the test.
Add test for rendering the reference images
Transmute the vector with the pixel instead of copying it. Fixes #78
Merge pull request #80 from nwin/master

Better tests