René Kijewski 162850b332 make: Implement optional features ... Fixes #1876 This PR introduces `FEATURES_OPTIONAL` which can be used to tell the Make system, that the application would like to use some feature, but the build should proceed even if the selected board cannot provide the optional feature. `make buildtest` and `make info-supported-boards` heed this variable when examining the list of supported boards. If a word is present in `FEATURES_REQUIRED` and `FEATURES_OPTIONAL`, then `FEATURES_OPTIONAL` takes precedence.		2014-10-26 23:18:58 +01:00
..
ccn-lite-client	core: adapt to msg_try_send	2014-10-22 12:37:33 +02:00
ccn-lite-relay	core: adapt to msg_try_send	2014-10-22 12:37:33 +02:00
default	make: Implement optional features	2014-10-26 23:18:58 +01:00
hello-world	boards: initial import of iot-lab_M3	2014-08-21 17:53:37 +02:00
ipc_pingpong	boards: initial import of iot-lab_M3	2014-08-21 17:53:37 +02:00
riot_and_cpp	examples: blacklisted openmote for riot_and_cpp	2014-10-24 15:34:15 +02:00
rpl_udp	core: adapt to msg_try_send	2014-10-22 12:37:33 +02:00