Reorganize annotations

[haegardev]

Putting annotations in exploded json files takes a lot of space per pcap file. Put an additional (json) file besides the pcap file with the annotation data and relying on compressed pcap data for the original data. The additional index should include the frame.number. Hence, the lookup could be made with tshark -n -r test.cap frame.number==x where x is the frame number.