Merge branch 'refs/heads/develop'
Removed util from require
Updated to version 0.0.2
Moved cwebp to same dir as exporter
Updated config to new format
Fixed default extension
Lots of bug fixes. See detailed description

Fixed bug for calculating the amount of source images
All source images now get copied to a tmp directory to protect the original images
Added chmod on tmp and output directory to avoid conversion fails
Updated to version 0.0.3
Merge branch 'refs/heads/master' into develop