Ctools css cache creates thousands of files

The function ctools_css_cache() provides a convenient way to cache generated css to files.
But used carelessly also provides an easy way to fill up the ctools/css cache directory with thousands of identical files.

The function takes the generated css, creates an md5-hash as file name and stores the file to the ctools/css directory – renaming when it already exists.
As the md5-hash for the file name is based on the contents of the file to be cached, I think its safe to assume that two files with the same file name are identical and the file can be replaced or discarded. Either way it's better as to flood the disk with useless files.