cmfs: basic journal support to cmfs

This patch adds basic journal support to cmfs. Currently the code only
passes gcc compiling, more patches latter will include further
improvement.

NOTE: this patch also rename 2 patches,
0003-cmfs-implement-early-mount-code.patch -> 0003-cmfs-basic-mount-implementation.patch
0004-cmfs-jbd2-journal-support.patch -> 0004-cmfs-basic-jbd2-journal-support.patch