[Cin] flac 1.4.0

[Andrea paz]

> i guess you forgot to alter configure.ac, re-run autgon.sh and may be move away flac 1.3.2 tar from thirdparty/src (so build system become confused about where flac libs actually located)

Yes, you are right. I had not modified configure.ac. Now I have no
errors and CinGG works fine, thanks.

I did a rendering test (audio only).
With the old flac:

9063 frames; render in 2.08s; 4340 fps.

With the new flac-1.4.0:

9063 frames; render in 4.471s; 2027 fps.

Basically, the rendering speed has halved. In my opinion, it is not
worth upgrading (it was better to keep the "useless" optimizations in
assembly!).