mkfs.cramfs: add endianness support to cramfs tools

mkfs.cramfs: add endianness support to cramfs tools

cramfs is an endianness dependent file system.  So far, the cramfs
utilities did not support cramfs images of different endianness than
the host machine.

A separate utility, cramfsswap, was required in order to change the
endianness of the image before and after using cramfs utilities. The
extra utility introduced extra maintenance and an additional step in
the process.

This patch adds endianness support to mkfs.cramfs and fsck.cramfs.
fsck.cramfs now automatically detects the image endianness, and can
work on images of either endianness.  mkfs.cramfs now accepts a new
optional parameter (-N) that allows creating the cramfs image in
either endianness.

Signed-off-by: Roy Peled <the.roy.peled@gmail.com>
Signed-off-by: Karel Zak <kzak@redhat.com>