squash commit of f2fs support commits by arter97
Makefile: remove -w flag
gitignore updated
fs: default to noatime/nodiratime
fs: import f2fs from git://git.kernel.org/pub/scm/linux/kernel/git/ja…
selinux: whitelist f2fs
afsync: extend to f2fs
f2fs: AIO optimization compatibility fix-ups
Makefiles: compiler option overhaul

Change-Id: I48b3b7922051f2b4bc954fe9a0ac2daa4441e80f