Croppa regex pattern

Add rest of the path up to croppa's extension

(.+)

Check for the size bounds

-([0-9_]+)x([0-9_]+)

Check for options that may have been added

(-[0-9a-zA-Z(),\-._]+)*

Check for possible image suffixes

\.(jpg|jpeg|png|gif|JPG|JPEG|PNG|GIF)$