Some flamegraphs are extremely slow to render

[itamarst]

For example, see the attached file at jonhoo/inferno#256 (comment), created by profiling import hymd. Probably the fact it has lots of small thin columns?

This probably will need some work upstream (jonhoo/inferno#256) but should at least try to mitigate it in Fil in the short term (and Sciagraph too, insofar as it shares that code, I forget).

[itamarst]

#264 would probably also help with this, because it would mean shorter text so less looping as the text shrinked in the flamegraph resize code, until upstream is fixed.