Possible solution for issue #175
thumbnails now are generated even, if only the high resolution image is missing
Default is to not generate @2x thumbnails
Fixed all open annotations by SmileyChris
Added unit test to check generation of high resolution files
Fixed annotation 2 of #175
Moved test_high_resolution into try block and restored thumbnail_high_resolution in finally
Using os.path.splitext instead of string.split to get filename extension
Ignore *.pyc in git status
Merge branch 'retina-display' of https://github.com/jrief/easy-thumbnails

Conflicts:
	easy_thumbnails/files.py
Update settings docs to use attr docstrings
Add docs for the THUMBNAIL_HIGH_RESOLUTION setting
Update AUTHORS
Remove TODO file
Use an attribute for Thumbnailer high-resolution
1.3