tools: add scons (patch by Dave Taht)

This makes it more possible to build scons based applications
for openwrt.

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@31618 3c298f89-4303-0410-b956-a3cf2f4a3e73

include/scons.mk

@@ -0,0 +1,21 @@
+SCONS_VARS = \
+	CC="$(TARGET_CC)" \
+	CXX="$(TARGET_CXX)" \
+	CFLAGS="$(TARGET_CFLAGS) $(EXTRA_CFLAGS)" \
+	CXXFLAGS="$(TARGET_CFLAGS) $(EXTRA_CFLAGS)" \
+	CPPFLAGS="$(TARGET_CPPFLAGS) $(EXTRA_CPPFLAGS)" \
+	LDFLAGS="$(TARGET_LDFLAGS) $(EXTRA_LDFLAGS)" \
+	DESTDIR="$(PKG_INSTALL_DIR)"
+
+define Build/Configure/Default
+	(cd $(PKG_BUILD_DIR); \
+		$(SCONS_VARS) \
+		scons \
+			prefix=/usr \
+			$(SCONS_OPTIONS) \
+		install \
+	)
+endef
+
+define Build/Compile
+endef