analyze_clients.py fixes

See merge request !26

Previously the loop ignored data points in range
10**int(log10(max(data)) to max(data).

Sometimes this range might have been empty already so not _all_
previous results are neccesairly invalid.

This is order of magnitude faster than dpkt implementation.

bufsize: decrease default buffer size to 2k & improve logging

See merge request !25

dnsjit pcap processing scripts

Closes #19

See merge request !24

Avoid creating long unique strings which trigger GC and slow down the
loop. Shorter non-unique string are deduplicated, leading to less GC and
faster processing.