MINOR: http-rules: Add more return codes to let custom actions act as normal ones

MINOR: http-rules: Add more return codes to let custom actions act as normal ones

When HTTP/TCP rules are evaluated, especially HTTP ones, some results are
possible for normal actions and not for custom ones. So missing return codes
(ACT_RET_) have been added to let custom actions act as normal ones. Concretely
following codes have been added:

 * ACT_RET_DENY : deny the request/response. It must be handled by the caller
 * ACT_RET_ABRT : abort the request/response, handled by action itsleft.
 * ACT_RET_INV  : invalid request/response