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.
Merge pull request #72 from nwin/master

Switch to new byte string syntax for chunk name matching.
Add ImageBuf::into_vec
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.