WINGs: Fix incorrect use of macro USE_PANGO in installed header

The header "WINGsP.h" needs different behaviour depending on whether the
support for Pango was enabled or not. But the related macro USE_PANGO is
defined by WindowMaker's configure, and after this header have been
installed the macro is no more valid.

This patch makes the "WINGsP.h" a generated file, so it will be different
depending on USE_PANGO, but will not make use of the macro itself.

As a side effect of being now generated, the include paths in the makefile
have been updated to include build-dir too, because for users doing an
out-of-tree build the generated file (that is used during compilation) is
placed in the build-dir.

Signed-off-by: Christophe CURIS <christophe.curis@free.fr>

WINGs/WINGs/Makefile.am

@@ -5,4 +5,14 @@ AUTOMAKE_OPTIONS =
 # is this a kluge? if so, how should i do it?
 includedir = @includedir@/WINGs
 
-include_HEADERS = WINGs.h WUtil.h WINGsP.h
+BUILT_SOURCES = WINGsP.h
+CLEANFILES = WINGsP.h
+include_HEADERS = WINGs.h WUtil.h
+nodist_include_HEADERS = WINGsP.h
+EXTRA_DIST = WINGsP.h.in
+
+WINGsP.h: WINGsP.h.in $(top_builddir)/config.h
+	$(AM_V_GEN)$(top_srcdir)/script/replace-ac-keywords.sh \
+		--header "$(top_builddir)/config.h" \
+		--filter "USE_PANGO" \
+		-o $@  $<

WINGs/WINGs/WINGsP.h.in

@@ -5,9 +5,7 @@
 #include <X11/Xlib.h>
 #include <X11/Xutil.h>
 
-#ifdef USE_PANGO
-#include <pango/pango.h>
-#endif
+@USE_PANGO@#include <pango/pango.h>
 
 #include <WINGs/WINGs.h>
 
@@ -459,9 +457,7 @@ typedef struct W_Font {
     short refCount;
     char *name;
 
-#ifdef USE_PANGO
-    PangoLayout *layout;
-#endif
+@USE_PANGO@    PangoLayout *layout;
 } W_Font;
 
 #define W_FONTID(f)		(f)->font->fid