Add some FEATURE macros for some UFS features.

SU+J is not included as a FEATURE macro:
 - it was not in the tree during the GSoC
 - I do not see an option to en-/disable it in NOTES

Two minor changes where made during the review compared to what was developed
during GSoC 2010.

No FreeBSD version bump, the userland application to query the features will
be committed last and can serve as an indication of the availablility if
needed.

Sponsored by:	Google Summer of Code 2010
Submitted by:	kibab
Reviewed by:	kib
X-MFC after:	to be determined in last commit with code from this project

sys/ufs/ffs/ffs_snapshot.c

@@ -124,6 +124,7 @@ ffs_copyonwrite(devvp, bp)
 }
 
 #else
+FEATURE(ffs_snapshot, "FFS snapshot support");
 
 TAILQ_HEAD(snaphead, inode);
 

sys/ufs/ffs/ffs_softdep.c

@@ -575,6 +575,9 @@ softdep_get_depcounts(struct mount *mp,
 }
 
 #else
+
+FEATURE(softupdates, "FFS soft-updates support");
+
 /*
  * These definitions need to be adapted to the system to which
  * this file is being ported.

sys/ufs/ufs/ufs_acl.c

@@ -57,6 +57,8 @@ __FBSDID("$FreeBSD$");
 
 #ifdef UFS_ACL
 
+FEATURE(ufs_acl, "ACL support for UFS");
+
 /*
  * Synchronize an ACL and an inode by copying over appropriate inode fields
  * to the passed ACL.  Assumes an ACL that would satisfy acl_posix1e_check(),

sys/ufs/ufs/ufs_vnops.c

@@ -82,8 +82,19 @@ __FBSDID("$FreeBSD$");
 #endif
 #ifdef UFS_GJOURNAL
 #include <ufs/ufs/gjournal.h>
+FEATURE(ufs_gjournal, "Journaling support through GEOM for UFS");
 #endif
 
+#ifdef QUOTA
+FEATURE(ufs_quota, "UFS disk quotas support");
+FEATURE(ufs_quota64, "64bit UFS disk quotas support");
+#endif
+
+#ifdef SUIDDIR
+FEATURE(suiddir, "Give all new files in directory the same ownership as the directory");
+#endif
+
+
 #include <ufs/ffs/ffs_extern.h>
 
 static vop_accessx_t	ufs_accessx;