Option to force use of "mime" instead of "mmmagic"

[bbak]

Since "mmmagic" has some issues (e. g. doesn't detect WOFF - at least on Debian, libmagic1 5.17-1), it may be feasible to have an option to force use of "mime" - and the possibility to add additional types/file-extensions to "mime".

[mihhail-lapushkin]

Done. See https://github.com/mihhail-lapushkin/grunt-css-url-embed#usemimetypesniffing for more details.
In case you need additional MIME-type mappings, please contact the author of mime.