can't create valid case 2b3 consens weight calculation

Even if legacy/trac#20284 (moved) is fixed, I still can come up with values that produce a Wed that is too large. Maybe I'm not trying hard enough, but I can't get case 2b3 to execute successfully.

For example, let

M=80
E=20
G=30
D=10
T=M+E+G+D

In case 2b2, Wed = (weight_scale*(D - 2*E + G + M))/(3*D) = 26667. That's bigger than weight_scale. It (and Wmd) trigger case 2b3, which doesn't do anything about a too large Wed and thus networkstatus_check_weights() fails.

I admit I don't know how reasonable the values are that I came up with above. I am writing test cases so legacy/trac#14881 (moved) can be closed though, and just about any weird combination should be handled without failing. Right?

I don't know what the correct resolution is, so not patch/branch incoming at this time.