SHELLERS for SYSCF, MacOS 10.5 hints file (trunk only)

Add SHELLERS - people allowed to use ! command with same syntax as WIZARDS.
Add new hints file for 10.5, since the rules and commands for groups changed
(new commands introduced in 10.4, old ones removed in 10.5; creating a new
user under 10.4 gave you a matching group, in 10.5 it doesn't).  Also move
shared build into roughly right place in file system when being installed
for root - don't use ~root.
Makefile.top - don't remove ./-p unless it exists (that's always annoyed me).
fix error invoking macosx.sh

src/sys.c

@@ -14,6 +14,7 @@ sys_early_init(){
 	/* replace use of WIZARD vs WIZARD_NAME vs KR1ED, by filling this in */
 #endif
 	sysopt.wizards = NULL;
+	sysopt.shellers = NULL;
 	sysopt.maxplayers = 0;	/* XXX eventually replace MAX_NR_OF_PLAYERS */
 }