Function renamed.

To be merged with STRING_FOR_EACH_TOKEN (FUNCTION renamed).
Minor changes.
string_first_token function added.
Options in pcap activate improved.

To be merged with IMPROVED OPTIONS.
Using new pfq_open_nogroup_ function.
Improved pfq handling with PFQ_TX_THREAD and PFQ_TX_QUEUE.
Minor changes in messages and error.
Experimental pcap_inject function added.