D20045: Add helper function to determine mime type based on content and extension

[Stefan Brüns]

bruns marked 3 inline comments as done.

REPOSITORY
  R286 KFileMetaData

REVISION DETAIL
  https://phabricator.kde.org/D20045

To: bruns, #baloo, #frameworks, astippich, ngraham, poboiko
Cc: kde-frameworks-devel, gennad, domson, ashaposhnikov, michaelh, astippich, 
spoorun, ngraham, bruns, abrahams