configure: Remove --disable-verbose-compile hack

Instead of using the --disable-verbose-compile hack, let's
use the standard option --enable-silent-rules (or 'make V=0' directly)
available with autoconf 1.11 and higher.

This is enabled in autoconf by using 'silent-rules' in AM_INIT_AUTOMAKE.
The verbosity of compilation is reduced in a similar manner as using
the --disable-verbose-compile option, so we can remove all that ugly
hackery.

WindowMaker/Defaults/Makefile.am

@@ -10,20 +10,20 @@ EXTRA_DIST = WMGLOBAL WMWindowAttributes.in WindowMaker.in WMState.in
 CLEANFILES = WMWindowAttributes WindowMaker WMState
 
 WMWindowAttributes: $(srcdir)/WMWindowAttributes.in
-	@-rm -f WMWindowAttributes
-	@sed -e "s:#extension#:@ICONEXT@:" \
+	-rm -f WMWindowAttributes
+	sed -e "s:#extension#:@ICONEXT@:" \
 		$(srcdir)/WMWindowAttributes.in > WMWindowAttributes
 	chmod 644 WMWindowAttributes
 
 WindowMaker: $(srcdir)/WindowMaker.in
-	@-rm -f WindowMaker
-	@sed -e "s:#pkgdatadir#:$(pkgdatadir):" $(srcdir)/WindowMaker.in \
+	-rm -f WindowMaker
+	sed -e "s:#pkgdatadir#:$(pkgdatadir):" $(srcdir)/WindowMaker.in \
 		> WindowMaker
 	chmod 644 WindowMaker
 
 WMState: $(srcdir)/WMState.in
-	@-rm -f WMState
-	@sed -e "s:#wprefs#:$(wpexecbindir)/WPrefs:" $(srcdir)/WMState.in > WMState
+	-rm -f WMState
+	sed -e "s:#wprefs#:$(wpexecbindir)/WPrefs:" $(srcdir)/WMState.in > WMState
 	chmod 644 WMState
 
 WMRootMenu: $(srcdir)/../plmenu

WindowMaker/IconSets/Makefile.am

@@ -8,10 +8,10 @@ EXTRA_DIST =
 CLEANFILES = Default.iconset
 
 Default.iconset: $(top_builddir)/WindowMaker/Defaults/WMWindowAttributes
-	@-rm -f Default.iconset
-	@echo '{' > Default.iconset
-	@grep Icon $(top_builddir)/WindowMaker/Defaults/WMWindowAttributes >> Default.iconset
-	@echo '}' >> Default.iconset
+	-rm -f Default.iconset
+	echo '{' > Default.iconset
+	grep Icon $(top_builddir)/WindowMaker/Defaults/WMWindowAttributes >> Default.iconset
+	echo '}' >> Default.iconset
 	chmod 644 Default.iconset