* Change the parameter of receive/send method on socket when working with signal: it now use a boolean (block or not) instead of a int for flags.
* Update travis-ci configuration and Makefile so that it builds on travis.
* large_string socket's test is disable when running on travis (because it requires too much memory)
Update documentation.
Merge pull request #57 from xaqq/socket_signal_pr

Signal receive send (and unrelated travis-ci)