[FEATURE] Detect file icons by mime-type

[FEATURE] Detect file icons by mime-type

Recognize files by the main part of the mime-type, provide icons for
the main parts audio, video, image and text. Allow registration and
overwriting of such mappings of file icons by mime-type.

Releases: master
Resolves: #69764
Change-Id: I9cc15157df2416c463e2105cc4bfb88a205e73b6
Reviewed-on: http://review.typo3.org/43039
Reviewed-by: Daniel Goerz <ervaude@gmail.com>
Tested-by: Daniel Goerz <ervaude@gmail.com>
Reviewed-by: Markus Klein <markus.klein@typo3.org>
Tested-by: Markus Klein <markus.klein@typo3.org>
Reviewed-by: Morton Jonuschat <m.jonuschat@mojocode.de>
Tested-by: Morton Jonuschat <m.jonuschat@mojocode.de>