Add -q to pngcrush to suppress it's output.
Merge pull request #34 from phallstrom/master

Add -q to pngcrush to suppress it's output.
Use system instead of backticks for pngcrush so file names with spaces are properly escaped
Merge pull request #36 from phallstrom/master

Use system instead of backticks for pngcrush so file names with spaces a...
updated release notes
bump version number
Merge branch 'master' of github.com:jakesgordon/sprite-factory