*: mass renaming of USE_XXXX to IF_XXXX
and SKIP_XXXX to IF_NOT_XXXX - the second one was especially
badly named. It was not skipping anything!

diff --git a/docs/new-applet-HOWTO.txt b/docs/new-applet-HOWTO.txt
index 6f89cbe..89df7d8 100644
--- a/docs/new-applet-HOWTO.txt
+++ b/docs/new-applet-HOWTO.txt
@@ -162,7 +162,7 @@
 Be sure to read the top of applets.h before adding your applet.
 
 	/* all programs above here are alphabetically "less than" 'mu' */
-	USE_MU(APPLET(mu, _BB_DIR_USR_BIN, _BB_SUID_NEVER))
+	IF_MU(APPLET(mu, _BB_DIR_USR_BIN, _BB_SUID_NEVER))
 	/* all programs below here are alphabetically "greater than" 'mu' */