final snappy fixes
updated Dynamic Fsync to latest version
random.c tweak
tweak writeback with Linus Torvalds values
update and enable compaction
decompressors: add lz4 decompressor module

This patch adds support for LZ4 decompression in the kernel.
LZ4 Decompression APIs for kernel are based on LZ4 implementation
by Yann Collet.

LZ4 homepage : http://fastcompression.blogspot.com/p/lz4.html
LZ4 source repository : http://code.google.com/p/lz4/

Signed-off-by: Kyungsik Lee <kyungsik.lee@lge.com>
lib: add support for LZ4-compressed kernels
finalize lz4 arm config
add compile dependency
lz4 compression succesful/clean makefile
config
Backport ROW from 3.8