Filter links by length slider not fine grained enough

[iimog]

The max value of the link length slider is in many cases estimated far too large. Further values can only set to ticks of the slider so for large genomes there might be no possibility to set it to e.g. 1000 as there are no intermediate ticks between 0 and 5000. There should be a means to set the exact value other than using the json editor. E.g. Instead of just showing the exact value in the text field above this could be editable.