create a globale configure/make

- move the configure from nominatim out and add checks for all dependencies
- bring module under automake control
- add osm2pgsql as a submodule, configure and build with the others

module/Makefile

@@ -1,6 +1,9 @@
 MODULES = nominatim
-PGXS := $(shell pg_config --pgxs)
+PGXS := /usr/lib/postgresql/9.1/lib/pgxs/src/makefiles/pgxs.mk
 include $(PGXS)
 
 all:
 	chmod 755 nominatim.so
+
+install:
+	@echo Library does not need to be installed.