Can't add addons from outside OF_ROOT + fix

I'm used to being able to add addons outside OF_ROOT by specifying their path relative to OF_ROOT/addons in addons.make, i.e:

ofxOSX
../../myExternalAddons/ofxJSON

This doesn’t work with the new makefiles anymore. This is because in config.project.mk there's some logic which decides what is a valid addon and what not. I've changed line 197 to not filterout INVALID_PROJECT_ADDONS and it now works again.

My suggestion is to not decide what is valid or what not or to make that logic include external addons. If there's something wrong in addons.make the user should fix it in addons.make. There shouldn't be any mistakes in addons.make in the first place. But I might not know the motivation behind deciding what's right and what's not?

Index: libs/openFrameworksCompiled/project/makefileCommon/config.project.mk
===================================================================
--- libs/openFrameworksCompiled/project/makefileCommon/config.project.mk    (revision 6903)
+++ libs/openFrameworksCompiled/project/makefileCommon/config.project.mk    (working copy)
@@ -194,7 +194,8 @@
     endif

     # create a list of addons, excluding invalid and platform-specific addons
-    PROJECT_ADDONS = $(filter-out $(INVALID_PROJECT_ADDONS),$(REQUESTED_PROJECT_ADDONS))
+    #PROJECT_ADDONS = $(filter-out $(INVALID_PROJECT_ADDONS),$(REQUESTED_PROJECT_ADDONS))
+    PROJECT_ADDONS = $(REQUESTED_PROJECT_ADDONS)

     ifdef MAKEFILE_DEBUG
         $(info ---PROJECT_ADDONS---)

Start in libs/openFrameworksCompiled/project/makefileCommon/config.project.mk, especially the logic around line 197 that filters INVALID_PROJECT_ADDONS from REQUESTED_PROJECT_ADDONS. Reproduce the addons.make case using an external path such as ../../myExternalAddons/ofxJSON, then verify that external addons are accepted without breaking the existing addon filtering behavior.