Apollo Track draws outside its boundaries when showing multiple regions

[garrettjstevens]

When viewing multiple regions, the Apollo Track is visible outside its own region, leading to weird visual glitches from the overlap of the regions:

The Apollo sequence track appears to be drawn mostly correctly, but should probably show the gray line that indicates a break in displayed regions.

[garrettjstevens]

When starting to work on this, I realized that out layout algorithm was laying things out for each displayed region, and there was no guarantee that a feature would end up on the same line in each region. This could lead to confusing layouts, especially if we try to do something like intron collapsing.

I've started work here on a new layout system that chooses a layout position for a feature only once and then uses it across regions: 721_fix_draw_outside_bounds.

[garrettjstevens]

This affects the six-frame display as well. See here viewing a gene in multiple regions (basically a region for each exon) vs. a single region.