rename #wizlevelflip to #wizfliplevel

Since ^V is dead key for me with Qt on OSX, I use #wizlevelport
instead.  It's annoying to have to type all the way up to the
'p' for it to become distinct.  Rename the biggest conflict,
\#wizlevelflip to #wizfliplevel.  I still have to type as far
as the first 'e' for #wizlevelport but 6 characters are easier
to type than 10.

It wasn't in the Guidebook so I've left things that way.  I am
adding it to 'wizhelp' though.

dat/wizhelp

@@ -20,9 +20,10 @@ Debug-Mode Quick Reference:
 #vanquished     == disclose counts of dead monsters sorted in various ways
 #vision         == show vision array
 #wizborn        == show monster birth/death/geno/extinct stats
+#wizfliplevel   == transpose the current dungeon level
 #wizintrinsic   == set selected intrinsic timeouts
 #wizmakemap     == recreate the current dungeon level
-#wizrumorcheck  == validate rumor indexing and show first, second, and last
+#wizrumorcheck  == validate rumor indexing; also show first, second, and last
                    random engravings, epitaphs, and hallucinatory monsters
 #wizsmell       == smell a monster
 #wizwhere       == show dungeon placement of all special levels