Refactor enmasse() and recurse() to reflect depth

The HLP-changes to sbase have been a great addition of functionality,
but they kind of "polluted" the enmasse() and recurse() prototypes.
As this will come in handy in the future, knowing at which "depth"
you are inside a recursing function is an important functionality.

Instead of having a special HLP-flag passed to enmasse, each sub-
function needs to provide it on its own and can calculate results
based on the current depth (for instance, 'H' implies 'P' at
depth > 0).
A special case is recurse(), because it actually depends on the
follow-type. A new flag "recurse_follow" brings consistency into
what used to be spread across different naming conventions (fflag,
HLP_flag, ...).

This also fixes numerous bugs with the behaviour of HLP in the
tools using it.

libutil/rm.c

@@ -10,10 +10,10 @@ int rm_rflag = 0;
 int rm_status = 0;
 
 void
-rm(const char *path, int flag)
+rm(const char *path, int depth)
 {
 	if (rm_rflag)
-		recurse(path, rm, 'P');
+		recurse(path, rm, depth);
 	if (remove(path) < 0) {
 		if (!rm_fflag)
 			weprintf("remove %s:", path);