BUILD: add --with-theme-manager configure option

src/htm/Makefile.am

@@ -0,0 +1,14 @@
+MDTOOL_OPTS = --verbose
+
+theme_SCRIPTS = thememan.exe thememan
+themedir = $(bindir)
+
+thememan.exe: htm-mono.csproj
+	$(MDTOOL) $(MDTOOL_OPTS) build $<
+
+thememan:
+	@echo "#!/bin/sh" > $@
+	@echo "exec mono /usr/bin/thememan.exe \"$@\"" >> $@
+
+clean-local:
+	rm -f thememan.exe thememan.exe.config thememan.exe.mdb thememan Main.resources