Use enumeration type to store the dump_file status
Set src and dst port to 0 for non-TCP/UDP packets

The source and destination ports are used to find the right bucket in the hash.
Currently they are only set when a TCP or UDP packet was detected and otherwise
the old (from previous packet) value is used. This is problematic when in the
future non-UDP/TCP traffic should be dumped because it will end up in different
pcap files.
Store allowed flow types in a common structure dump_allowed

It is easier to spot the right place which must be modified to add more flow
types when the configuration for them is stored the same way in a common
variable/structure.
Add option to enable dumping of non-UDP/TCP IP flows