add -lminixfs with fs support routines

. move cache size heuristic from mfs there
	  so mfs and ext2 can share it
	. add vfs credentials retrieving function, with
	  backwards compatability from previous struct
	  format, to be used by both ext2 and mfs
	. fix for ext2 - STATICINIT was fed no.
	  of bytes instead of no. of elements, overallocating
	  memory by a megabyte or two for the superblock

include/limits.h

@@ -83,7 +83,6 @@
 /* Some of these old names had better be defined when not POSIX. */
 #define _NO_LIMIT          100	/* arbitrary number; limit not enforced */
 
-#define NGROUPS_MAX          8	/* max. number of supplemental groups */
 #if _EM_WSIZE > 2
 #define ARG_MAX          262144 /* # bytes of args + environ for exec() */
 #else
@@ -113,6 +112,8 @@
 #define IOV_MAX        INT_MAX  /* maximum number of buffers for readv/writev */
 #endif /* _POSIX_SOURCE */
 
+#define NGROUPS_MAX          8	/* max. number of supplemental groups */
+
 #define GID_MAX		USHRT_MAX
 #define UID_MAX		USHRT_MAX