Remove relationCollections feature flag

Additional clean-ups include leaving a gap in the line for the indicator.

Undocumented updated for removed code; these were the only changes, but line-numbers changed quite a bit.  That file can be safely ignored.

```
app/views/topology/relation.js "subRelBlockMouseLeave" listed as undocumented but does not exist
app/views/topology/relation.js "subRelBlockMouseEnter" listed as undocumented but does not exist
Backlog of undocumented functions: 110
```