rename of M_ alloc defines

[Hiten Pandya]

Eirik Nygaard wrote:
Jeffrey Hsu wondered if I could rename the mbuf alloc flags M_TRYWAIT,
M_DONTWAIT and M_WAIT to be MB_ instead. So they would not be confused
with the malloc flags in the kernel.
I will commit the patch on monday if there are nothing I missed.

http://eirikn.kerneled.org/dragonfly/M_toMB_inallocoperations.patch
	You still need to rename the libmchain flags as I have mentioned
	quite a few times before.  They are named MB_*, and they should
	be renamed to MBC_* to avoid confusion.
		-Hiten
		hmp at xxxxxxxxxxxxx