Initial non-blocking connect support

Disabled hostname and wildcard backends to implement initial nonblocking
connect support.
Fix memory leak
cleanup
Using an IP address literal in Travis-CI tests config
Merge branch 'master' into nonblocking-connect
Merge branch 'master' into nonblocking-connect

Conflicts:
	.travis.yml
	src/connection.c
Merge branch 'master' into nonblocking-connect

Conflicts:
	src/connection.c
	src/listener.c
Fix close_connection for additional states
Remove unnecessary MSG_DONTWAIT flag
Remove CONNECTING state
Avoid leaving connections in RESOLVED state when no route to backend server
Merge branch 'master' into nonblocking-connect
Merge branch 'master' into nonblocking-connect

Conflicts:
	.travis.yml
Merge branch 'master' into nonblocking-connect
Merge remote-tracking branch 'github/master' into nonblocking-connect

Conflicts:
	src/connection.c
Merge remote-tracking branch 'github/master' into nonblocking-connect
Merge branch 'master' into nonblocking-connect
Merge remote-tracking branch 'github/master' into nonblocking-connect

Conflicts:
	src/connection.c
Merge branch 'master' into nonblocking-connect
Update README.md