~humaid/ns2-trace-go

templates: Add notice on which packet types are calculated in the stats
Add lost packets, collisions, and average delay to stats.

Also make the website look better in smaller screens by adding margins.
And only show jitters for tcp, udp and cbr.
templates: Little fixes
Allow users to download jitter data as json
Speed improvement with concurrency when generating statistics and calculating jitter
Graphs: Fixed go-chart version in Go Mod, and allow selection of zoomed or full view for jitter