Major changes:
- make API more reusable
- format output nicely
- only force gc if needed
Regarding forcing gc:
Forcing gc can change script execution time.
We now don't force gc at first and ignore results where gc happens during script execution.
When we ignored too many results, we switch to forcing gc.
Closes#339
- use performance log of chromedriver / appium to get timeline data
for calculating metrics for benchmarks
- change all benchmarks to be made of a standalone application
and a protractor test that collectes timeline data
- fix and simplify benchmarks
- add dart2js to build
- remove benchpress
Closes#330