* upstart/control.c (upstart_read_int, upstart_write_int) 
(upstart_read_ints, upstart_write_ints, upstart_read_str) 
(upstart_write_str, upstart_read_header, upstart_write_header):
New functions to replace the old "write a struct" protocol with
something a little more regimented and supportable.
(IOVEC_ADD, IOVEC_READ, WireHdr, WireJobPayload, WireJobStatusPayload)
(WireEventPayload): Remove these structures, use the functions
instead.
(upstart_send_msg_to): Call write functions intead of using macros,
this makes the code somewhat neater.
(upstart_recv_msg): Call read functions instead of using macros,
again making the code somewhat neater.
* upstart/tests/test_control.c (test_recv_msg): Change wire
tests to match new protocol, and thus actually work properly,
previously these were endian sensitive.