Reduce memory

[xnvi]

1. I don't found any code use ‘’faacEncStruct.coderInfo.bwpInfo‘’ , remove ‘’bwpInfo‘’ can save about 157KB for each channel.
2. in function "faacEncEncode()"

if (!hEncoder->sampleBuff[channel])
    hEncoder->sampleBuff[channel] = (double*)AllocMemory(FRAME_LEN*sizeof(double));

tmp = hEncoder->sampleBuff[channel];

hEncoder->sampleBuff[channel]		= hEncoder->nextSampleBuff[channel];
hEncoder->nextSampleBuff[channel]	= hEncoder->next2SampleBuff[channel];
hEncoder->next2SampleBuff[channel]	= hEncoder->next3SampleBuff[channel];
hEncoder->next3SampleBuff[channel]	= tmp;

I think "nextSampleBuff" and "next2SampleBuff" is useless, so change it to this

hEncoder->sampleBuff[channel]		= hEncoder->next3SampleBuff[channel];
hEncoder->next3SampleBuff[channel]	= tmp;

can save 16KB for each channel.