Navigating between two genomes using synteny links

[mberriman]

Describe the bug
Some sequence similarity links only visible while actively scrolling left/right

To Reproduce Steps to reproduce the behavior:

1. Opening synteny view at
   SM_V10_3:9,650,822..10,153,093. (S. mansoni)
   CHR_3:8,288,810..8,791,081 (S. haematobium)

2. clicking on S. haematobium sequennce and drag the sequence left and right. While dragging, similarity blocks appear (at an extreme angle) but they disappear when you stop dragging

Expected behavior

The similarity blocks should be visible even when drawn and an extreme angle (i.e. connecting to a very distant locus) because this is an important navigation aid. Ideally user needs to be able to find an interesting locus in one genome by browsing etc. Then, using synteny bars, find the equivalent locus in the aligned genome.

Screenshots

screenshots from a Quicktime movie I've made

Version information:

JBrowse 2 3.7.0
ApolloPlugin 0.3.10