intra energy for low bitrates, and a bit of very high bitrate tuning

channels. Fixed two stereo bugs in the process: one in the handling of
mdct_weight_shift and one in the PLC.

de-interleaved

bands that weren't rounded down.

remaining bits for fine energy

directly instead of converting to dB and later dividing by 6.

Conflicts:
	libcelt/celt.c
	libcelt/celt.h

which allows the caller to request that frames be independent.

state before using it. Handle malloc failures for the encoder and
decoder setup gracefully and without leaks.