adding travis-ci

currently without make check, which did not run proper on travis (further investigation needed)
csocket_impl => revised tx-queue management: accept messages for transmission, as long as the socket is not returning EWOULDBLOCK, in state WOULDBLOCK, accept additional messages up to max_txqueue_size packets and throw exceptions
Merge branch 'devel-0.5' into devel-0.6
fix buffer overflow in cioloop
Merge branch 'devel-0.5' into devel-0.6
fixed test_ipv6
removed debug printf
csocket_impl => revised strategy for tx-queue management / crofshim => revised
Merge branch 'devel-0.6' of https://github.com/bisdn/rofl-core into devel-0.6
set c standard
travis updates

* silenced apt install
* moved autogen
* enabled make check
due to errors temporary disabled make check again...
crofsock => changing default max congestion windows
Merge branch 'devel-0.5' into devel-0.6
merged
of1x_action_pp.h => adding dump of packet matches to single port output for ActionOutput, when DEBUG is enabled (makes life a little bit easier for debugging)
Merge branch 'devel-0.5' into devel-0.6

Conflicts:
	configure.ac
	examples/Makefile.am