For now, I left the following instances because it isn't
clear to me why they are using the different values.
Maybe they need one-by-one inspection.
examples/igmp/Makefile:STACKSIZE = 1024
examples/powerled/Makefile:STACKSIZE = 1024
examples/powermonitor/Makefile:STACKSIZE = 768
examples/relays/Makefile:STACKSIZE = 512
examples/smps/Makefile:STACKSIZE = 1024
graphics/screenshot/Makefile:STACKSIZE = 4096
system/flash_eraseall/Makefile:STACKSIZE = 1024
testing/cxxtest/Makefile:STACKSIZE = 4096
testing/smart_test/Makefile:STACKSIZE = 4096