Include <sys/time.h> on all !win32 platforms

This removes compile warnings for unknown struct timeval

Change-Id: Ib669ebedf9b80dd1881c4d14920310284f364129
Reviewed-on: http://review.couchbase.org/41444
Reviewed-by: Trond Norbye <trond.norbye@gmail.com>
Tested-by: Trond Norbye <trond.norbye@gmail.com>