MFC r245820, r245844, r245950:

MFC	r245820, r245844, r245950:

ext2fs: make some inode fields match the ext2 spec.

Ext2fs uses unsigned fields in its dinode struct.
FreeBSD can have negative values in some of those
fields and the inode is meant to interact with the
system so we have never respected the unsigned
nature of most of those fields.

Block numbers and the generation number do
not need to be signed so redefine them as
unsigned to better match the on-disk information.

Include some fixes proposed by bde@.

While here add a lot of svn mergeinfo that was missing
in /sys:

r239963,240060,240880,241007,241141,241143,241181,243641,
243652,244475,245121,245612,245817

git-svn-id: svn://svn.freebsd.org/base/stable/9@246049 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f