Modifying ADDON_SOURCES in addons_config.mk

Hmm... Not quite sure what I changed but I've got it working now. Here is something that I noticed in the process, and maybe it is apparent to others... But maybe it could help someone in the future.

Adding MAKEFILE_DEBUG=true inside of the project's config.make showed that only one of the four ofxOpenNI/src files are actually being included:

---PROJECT_ADDONS_SOURCE_FILES---
/home/brannondorsey/Documents/code/of_v0.9.0_linux64_release/addons/ofxOpenNI/src/ofxOpenNI.cpp

Where I thought it should read:

/home/brannondorsey/Documents/code/of_v0.9.0_linux64_release/addons/ofxOpenNI/src/ofxOpenNI.cpp
/home/brannondorsey/Documents/code/of_v0.9.0_linux64_release/addons/ofxOpenNI/src/ofxOpenNI.h
/home/brannondorsey/Documents/code/of_v0.9.0_linux64_release/addons/ofxOpenNI/src/ofxOpenNITypes.h
/home/brannondorsey/Documents/code/of_v0.9.0_linux64_release/addons/ofxOpenNI/src/ofxOpenNIUtils.h

But apparently ADDONS_SOURCES only finds .cpp files, not .h files. For that you've got to use ADDONS_INCLUDES.