#93 sort, group, colorize by extension (plugin)

[graceman9]

I wish plugin which can ( sort | group | colorize ) filenames by extension.
For example, in web-dev: php, js, css, html - I want to divide this files when about 10-20 files is opened.
Maybe (or not) I can do this, like in 'doclist' plugin, but I haven't some functions like document_compare_by_ext..