add support for build system overlays that alter package build instructions currently unused, will probably be managed by the feeds system later

SVN-Revision: 17445

include/package.mk

@@ -145,7 +145,14 @@ define Build/DefaultTargets
   distcheck: $(STAMP_CONFIGURED)
 endef
 
+define Build/IncludeOverlay
+  $(eval -include $(wildcard $(TOPDIR)/overlay/*/$(PKG_NAME).mk))
+  define Build/IncludeOverlay
+  endef
+endef
+
 define BuildPackage
+  $(Build/IncludeOverlay)
   $(eval $(Package/Default))
   $(eval $(Package/$(1)))
 

include/toplevel.mk

@@ -43,7 +43,7 @@ prepare-mk: FORCE ;
 
 prepare-tmpinfo: FORCE
 	mkdir -p tmp/info
-	$(_SINGLE)$(NO_TRACE_MAKE) -j1 -r -s -f include/scan.mk SCAN_TARGET="packageinfo" SCAN_DIR="package" SCAN_NAME="package" SCAN_DEPS="$(TOPDIR)/include/package*.mk" SCAN_DEPTH=5 SCAN_EXTRA=""
+	$(_SINGLE)$(NO_TRACE_MAKE) -j1 -r -s -f include/scan.mk SCAN_TARGET="packageinfo" SCAN_DIR="package" SCAN_NAME="package" SCAN_DEPS="$(TOPDIR)/include/package*.mk $(TOPDIR)/overlay/*/*.mk" SCAN_DEPTH=5 SCAN_EXTRA=""
 	$(_SINGLE)$(NO_TRACE_MAKE) -j1 -r -s -f include/scan.mk SCAN_TARGET="targetinfo" SCAN_DIR="target/linux" SCAN_NAME="target" SCAN_DEPS="profiles/*.mk $(TOPDIR)/include/kernel*.mk $(TOPDIR)/include/target.mk" SCAN_DEPTH=2 SCAN_EXTRA="" SCAN_MAKEOPTS="TARGET_BUILD=1"
 	for type in package target; do \
 		f=tmp/.$${type}info; t=tmp/.config-$${type}.in; \