Merge branch 't/sync'

Merge branch 't/sync'

Cooking since 2014-01-14.

	* t/sync:
	  The sync filter.
	  net: Let maksock() callers perform flowopt cleanup.
	  net: makesock_addrinfo(): Make socketfd local to the loop.
	  net: Let makesock() continue on setsockopt() failure.
	  net: Reduce indentation level in makesock_addrinfo().
	  net: Further simplify makesock_addrinfo().
	  net: Replace the double loop of lookup_address() by a single loop.
	  net: makesock(): Combine code for passive sockets.
	  net: Change makesock_addrinfo() to set given flowopts before SO_REUSEADDR.
	  net: Clarify code flow of makesock_addrinfo().
	  net: Remove unnecessary condition in makesock_addrinfo().
	  net: Remove pointless initialization in makesock_addrinfo().
	  net: Kill dead code in makesock_addrinfo().
	  net: Remove networking headers from para.h.
	  net: Improve error handling of makesock_addrinfo().
	  net: Split makesock(), part 2: Introduce makesock_addrinfo().
	  net: Split makesock(), part 1: Introduce lookup_address().
	  net: Simplify makesock().
	  net: Fix parse_url().
	  net: Correct \return text of parse_url().