#933 Add some formats inside .desktop files

[Delerue]

Currently, Qmmp for Linux doesn't include the following xdg formats:

audio/aac
audio/x-aac
audio/m4a
audio/x-m4a

So, although Qmmp can actually open these files, there's no default association with Qmmp. This should be included in both qmm.desktop and qmmp_enqueue.desktop

[trialuser02]

Fixed in [r7414].