Doxygen uses comments in the source code to generate documentation.
This commit just adds the descriptive headers and marks current
comments and appropriate for inclusion in the API docs. Many
symbols remain undocumented. See the warnings from the build output.

This is now part of the bit-stream

Now has tuning parameters for mono/stereo and voice/music. Also switches
to stereo during swb and without reducing the bandwidth.

Doesn't work for fixed-point for some unknown reason

Gregory Maxwell authored 13 years ago and Jean-Marc Valin committed 13 years ago

The object code is unchanged (except ectest). Also reenables -Wparentheses, -Wsign-compare,
and the MSVC warnings.

Removes a bunch of system #include <...> in the process

The SILK bandwidth was incorrectly encoded in the ToC when SILK wasn't
using the "desired bandwidth"