Improve error reporting messages for NoSpritesFoldersFoundError and SourceImagesNotFoundError #61
Bump version to 0.2.9
Add 0.2.9 as part of the changelog
Added variable "identifier" to --each-template

In some cases its necessary to adjust the x- and y-values for the background-positions of some sprites. Of example to center a sprite image which is used for bullet points.

With the variable "identifier" its possible to create @LessVariables for x- and y-values in each-template to use them in own Less files.
Python header files are required to build modules
Make glue require Pillow 1.7.8 in order to fix some segmentation errors. #19
Add Lars Pe to the AUTHORS file
Update changelog
Fix ProjectSpriteManager #66
Bump version
Update copyright
Bump version
Make glue use ImageMagick to scale down retina sprites
Update --imagemagick and retina documentation
Remove soft 2px default for margin when using --ratios or --retina
Remove test__margin
Fix glue if you generate sprites only with pseudo classes #77
Add some test about pseudo class sprites #77
Fix camelcase separator not preserving original case #74
Update changelog