optimize swap_buffer function, do a word per step
shine_putbits bug fix!

1. If cache_bits is 0, and N is 32, the result is wrong.
2. The last 4 bytes of the lastest frmae will be lost.
Debug message
Add shine_get_bits_count function.

Remove the summation of bits in WitePartSideInfo and write_side_info functions.
cleaup WitePartSideInfo function
cleaup WritePartMainData function
Indentation
make WitePartSideInfo and WritePartMainData inline
cleanup BF_LoadHolderFromBitstreamPart function
Cleanup code relative to bitstream.

Remove lots of unnecessary malloc, free and assignment.
bug fix
Reimplement bitstream.

Shine is very fast now, and footprint is very small!
Remove missing header.
Merge branch 'zhaoxiu-zeng'