addons_config

this removes the per platform folders in src and adds an addons_config.mk that configures the PG and makefiles to generate the projects

it seems to work for me in win_cb but then the app complains that it's missing a libusb dll. so not sure if i'm including/excluding the right files. there seems to be 2 libusbs and some remaining libs from vs2010 that should be removed but not sure which of those are correct