#608: Bash 'web_img', implement 'extglob'
#608: Bash 'web_img', reorder code
#608: Bash 'web_img', do not minify 'gif' files
#608: Bash 'web_img', remove 'extglob' implementation
#608: Bash 'web_img', adjust 'file_extension' definition
#608: Bash 'web_img', use 'expansion' notation
Merge pull request #610 from jeff1evesque/bash_web_img

#608: Imagemin ruins '.gif' images on minification