Combine all bandwidth graphs to condense and consolidate graph display

[Reportage]

If both inbound and outbound bandwidth is configured for graphing for a single tunnel, automatically combining the graphs as per router bandwidth would help condense the display of information on /graphs, notably where many graphs are configured.

This would still permit the display of a tunnel's bandwidth in a single direction as a single graph if only inbound or outbound graphing was configured (not both), but would combine the graphs in the event both inbound and outbound bandwidth for a tunnel is configured for display. An optional config could determine whether graphs should be automatically combined, defaulting to auto-combine.

[zzz]

Yeah I think we've talked about this before, at least generally. The current combined graph is a hardcoded special case. I don't know how to do a UI for configuration of combo graphs, but more special cases is also a challenge. Auto-combining more things is feasible but may be a little messy. If we did it we'd just do it, not make it configurable (via UI or not). Not a bad idea.

[Zlatin Balevsky]

From IRC, reproduced here with permission from Arctic:

[11:30am] arctic: [12:30] .:dr|z3d:. SummaryRenderer.java around line 123 for the combined graphs.