patch for TS-2834

This patch adds a condition "INTERNAL-TRANSACTION' and makes the client IP '%<chi>' available for COND arguments. Usage examples

cond %{READ_REQUEST_HDR_HOOK} [AND]
cond %{INTERNAL-TRANSACTION} [NOT]
rm-header client_ip
add-header client_ip %<chi>

cond %{READ_REQUEST_HDR_HOOK} [AND]
cond %{%<chi>}  =127.0.0.1 [NOT]
rm-header client_ip
add-header client_ip %<chi>