Pathtracer improvements: trace folding and respects bytecode option.

Path tracer HTML output now respects --path-trace-report-bytecode, which is useful for producing MUCH smaller html files.
Improvements to display options in HTML trace report

1. Added new display options (toggling mouse events and load events).

2. This is now implemented by modifying the class of the parent list, instead of every affected element, making the logic a bit clearer and easier to update.

3. Traces are collapsed by default, which makes it easier to get an overview of the report.
Merge branch 'master' of github.com:cs-au-dk/Artemis