always properly exit client in case of failure or bad use
set reuse_address option on socket
Not sure if this should be enabled by default but
 it helps development
fix cmake build
no lock when calling callbacks, keep shared_ptr to
server object in callback to make sure it is not
 destroyed before callback
do not hardcode linker flag
remove obsolete comment
re-enable python tests in travis
Merge pull request #93 from oroulet/master

diverse fixes