[WIP] Add hevc support to amlcodec

Test files: http://www.semperpax.be/owncloud/public.php?service=files&t=8c1e200bd98fd7b604c09a1d1c7e9b20

~~- Should merge the work from https://github.com/xbmc/xbmc/pull/5374 regarding hevc annex-b~~ DONE, a patch to the PR is needed, though.
- Needs 666 on /dev/amstream_hevc