Change in wireshark dissector

modified:   utilities/wireshark_dissectors/openflow/packet-openflow.c
I was trying to run multiple controllers and capture the openflow packets using this dissector. As it turns out it cannot listen to multiple ports, hence support multiple controllers at the same time. The dissector is modified to support both a single port and a range of ports.

The following variables in Makefile need to be changed
 
DISSECTOR_PORT_TYPE -> Specifies whether a single port 
(-DOPENFLOW_DST_TCP_PORT_TYPE=0) or a range of ports 
(-DOPENFLOW_DST_TCP_PORT_TYPE=1) will be used

DISSECT_PORT -> for single port only, same as before
DISSECT_PORT_START -> start of the range, e.g., 
-DOPENFLOW_DST_TCP_PORT_START=7000 

DISSECT_PORT_END -> end of range, e.g.,
-DOPENFLOW_DST_TCP_PORT_END=8000