Syslog seems to block entering in screen copymode... verbose mode drops
messages allowing pyfcgi to continue.

Add missing ./ in front of src/pyfcgi

Add a -l --listen option to set the socket path or address:port
Fix a bug using thread safe functions from libfcgi

uwsgi do not handle str, only bytes.

When using the debug build of python, assserts raises en freeze pyfcgi telling
a decref is run on a thing with visit count == 0....