Fix source address IPHC
posix: Disable debug output of pthreads

`DEBUG_ENABLED` should be enabled during debugging, and disabled
afterwards.
Auto init source address mode
Fix test_net_if
Merge pull request #852 from authmillenon/autoinit-src-addr-mode

net_if/auto_init: Auto init source address mode
Merge pull request #843 from authmillenon/fix-lowpan-iphc

sixlowpan: Fix source address IPHC
Merge pull request #848 from Kijewski/that-annoying-debug-flag-in-pthread-that-effing-needs-to-go-away-already

posix: Disable debug output of pthreads
Merge pull request #853 from authmillenon/fix-test-net-if

tests: Fix test_net_if
posix: added netdb
libcoap: use blocking io
coap: import etsi test cases