makefile: fix make cfg when the cfg vars are already exported

- when make cfg was called with the cfg vars already exported it
  failed to generate a proper config.mak (e.g. called from
  make deb)
- extra config sanity check
- s/mysql/db_mysql in the mysql module group
-  added "deb" to the list of targets that don't need dependencies
   (minor optimization)

Makefile

@@ -156,8 +156,8 @@ module_group_standard_dep=acc_db acc_radius auth_db auth_radius avp_db \
 				presence_b2b rls speeddial uri_db xcap xmlrpc
 
 # For mysql
-module_group_mysql=acc_db auth_db avp_db db_ops uri_db domain lcr msilo mysql\
-				speeddial
+module_group_mysql=acc_db auth_db avp_db db_ops db_mysql uri_db domain lcr \
+					msilo speeddial
 
 # For radius
 module_group_radius=acc_radius auth_radius avp_radius misc_radius peering
@@ -264,6 +264,9 @@ ifeq ($(makefile_defs),1)
 $(info config.mak loaded)
 # config_make valid & used
 config_mak=1
+ifeq ($(MAIN_NAME),)
+$(error "bad config.mak, try re-running make cfg")
+endif
 endif
 else # config.mak doesn't need to be used
 ifneq (,$(filter cfg config cfg-defs,$(word 1,$(MAKECMDGOALS))))
@@ -273,6 +276,9 @@ ifneq (,$(filter cfg config cfg-defs,$(word 1,$(MAKECMDGOALS))))
 # $(value ...) expansion or would cause some warning (if Makefile.defs exec. 
 # is skipped in the "main" makefile invocation).
 $(shell rm -rf config.mak)
+config_mak=0
+makefile_defs=0
+exported_vars=0
 endif
 endif
 

Makefile.cfg

@@ -14,6 +14,7 @@
 #create config if needed
 $(COREPATH)/config.mak: makefile_defs=0
 $(COREPATH)/config.mak: exported_vars=0
+$(COREPATH)/config.mak: config_mak=0
 
 $(COREPATH)/config.mak: $(COREPATH)/Makefile.defs
 	$(MAKE) -wC $(COREPATH) cfg-defs

Makefile.targets

@@ -35,7 +35,7 @@ doc_targets:=	README man install-doc install-man install-ser-man \
 # auxiliary: maintance, debugging, etc. (don't affect code/objects)
 aux_targets:=	TAGS tar dist cfg-defs cfg config config.mak print-modules \
 		dbg dbinstall librpath.lst makecfg.lst modules.lst modules-cfg \
-		modules-list modules-lst mk-install_dirs autover.h
+		modules-list modules-lst mk-install_dirs autover.h deb
 # other targets that don't produce code in the current directory ("external")
 ext_targets:=	every-module $(modules_dirs) libs utils \
 		install-cfg install-utils  install-modules-all install-every-module\