DVDVideoCodecFFmpeg: Do not set AVCodecContext.dsp_mask.

Setting it to 0 is useless since it is the default (meaning autodetection) and this variable is deprecated.
[WIN32] switched from internal liblame to external (3.99.5) and download it from our mirrors. /lib/liblame can be removed if no one else uses it.
[AE/CA] - no need for the streamsilence / idle suspend stuff on ios - so do it only for osx
Fix format string which causes compilation error when --enable-dvdcss is set on Ubuntu
Merge pull request #2123 from aballier/no_dsp_mask

DVDVideoCodecFFmpeg: Do not set AVCodecContext.dsp_mask.
Merge pull request #2125 from hrodenburg/fix-format-string

Fix format string which causes compilation error when --enable-dvdcss is...
[language] add reference in what files current string ids are used