test_ltc4150: fix Makefile

use BOARD_WHITELIST
remove hwtimer
remove cruft
style improvements
Merge pull request #99 from LudwigOrtmann/test_ltc4150

test_ltc4150: fix Makefile
add olsr example application
adapt to changes in the network stack
use net_if_set_src_address_mode
add new posix include path to fix the build