Fix path substitutions

Autoconf uses multiple levels of variables when defining paths. For
example, ${datadir} by default is ${datarootdir}, which by default is
${prefix}/share, which by default is /usr/local. Substituting from
./configure, as is done by AC_DEFINE or AC_DEFINE_UNQUOTED, does not
expand all these variables. This was causing some of our defines to have
garbage like "${prefix}/share/pixmaps" rather than the intended
"/usr/local/share/pixmaps".

The solution is to generate the files needing these paths from the
Makefile rather than from ./configure, because make does fully expand
all those levels.

Signed-off-by: Brad Jorsch <anomie@users.sourceforge.net>

Makefile.am

@@ -1,5 +1,34 @@
 ## Process this file with automake to produce Makefile.in
 
+AUTOMAKE_OPTIONS =
+
+BUILT_SOURCES = config-paths.h
+
+DISTCLEANFILES = config-paths.h
+
+config.h: config-paths.h
+
+config-paths.h: Makefile
+	@echo "Generating $@"
+	@echo '/* define to the path to cpp */' > $@
+	@echo '#define CPP_PATH "$(CPP_PATH)"' >> $@
+	@echo '' >> $@
+	@echo '/* gettext domain used for menu translations */' >> $@
+	@if test -z "$(menutextdomain)"; then \
+	  echo '/* #undef MENU_TEXTDOMAIN "$(menutextdomain)" */' >> $@; \
+	else \
+	  echo '#define MENU_TEXTDOMAIN "$(menutextdomain)"' >> $@; \
+	fi
+	@echo '' >> $@
+	@echo '/* define an extra path for pixmaps */' >> $@
+	@echo '#define PIXMAPDIR "$(pixmapdir)"' >> $@
+	@echo '' >> $@
+	@echo '/* where shared data is stored */' >> $@
+	@echo '#define PKGDATADIR "$(pkgdatadir)/WindowMaker"' >> $@
+	@echo '' >> $@
+	@echo '/* where the configuration is stored */' >> $@
+	@echo '#define SYSCONFDIR "$(sysconfdir)"' >> $@
+
 ACLOCAL_AMFLAGS = -I m4
 
 SUBDIRS = wrlib WINGs src util po WindowMaker WPrefs.app doc