cmfs-tools: more fix on cmfs clusters setting

This commit adds following changes,
1) add cmfs_rec_blocks()
2) wrap a cmfs_rec_clusters() based on cmfs_rec_blocks()
3) change cluster variable width from 32bits to 64bits in
cmfs_blocks_to_clusters() and cmfs_rec_clusters().
cmfs-tools: important typo fixes in libcmfs/inode.c

This commit fixes 2 important typo in 3 places, which are,
1) invalid block number range check, fix (blkno < fs->fs_blocks) to (blkno >
fs->fs_blocks)
2) replace memcpy() by memcmp() when checking inode signature.
cmfs-tools: use mkfs_set_rec_blocks() in mkfs.cmfs/mkfs.c

mkfs.cmfs/mkfs.c uses mkfs_set_rec_clusters() to set data extent
internal/leaf cluster size, indeeded currently we use blocks other than
clusters in internal/leaf data size identifying, which will always
result a 0 cluster. So extent iteration code will not iterate directory
blocks ad expected.

This patch fixes this bug by using mkfs_set_rec_blocks() to replace
mfks_set_rec_clusters(), and add other changes which are related to this
change.