add support for flac --> aac about flac2all HOT 5 OPEN

Wow, I didn't even publicise the fact that AAC support is being added, and I've 
already got opinions on which encoder to use :)

We are currently using mp4tools, but it does seem rather limited. Nero's AAC 
codec is good, but there are some issues with it, namely:

a) It is closed source
b) Due to the above, it is only available for the x86 arch and Linux, which 
might not be what people are using this script on.
c) Incompatible with free software

Now, faac is apparently nowhere near as good, in fact Nero's AAC is pretty much 
the best option by a long shot on Linux. 

So what I'll probably do is provide both neroAAC and faac. 

Well, revision 21 now uses the NeroAAC encoder. Feel free to give it a go! 
Works for me, but you'll need neroAacEnc in your $PATH for it to work. 

Stable version now has AAC+ suppot with the NeroAAC encoder. I still would like 
to find some way of tagging AAC in unix, and provide an open source encoder 
implementation. 

Leaving ticket open as "Started", and we'll see how things go in future. 

ffmpeg now supports libfdk_aac. What are your thoughts about that?

https://trac.ffmpeg.org/wiki/GuidelinesHighQualityAudio

Hmm, that is interesting. Although I wonder if flac2all should just implement 
AAC ffmpeg encoding, or a more generic library for using any of ffmpeg's codecs 
(it would go quite a bit further in the "2all" part of the project name). 

However, I'm not sure if ffmpeg supports tagging, so  will have to have a look. 

Thanks for the tip!