Import speed test benchmark code from esprima.

Bootstrap-ify it, and other random tweaks to decouple it from esprima codebase.
Add makefile command to slurp together all the turtlescript sources.
Fix a CSS error in the asmjs validator.
Add TurtleScript parser to speed comparison benchmark page.

Also change the test suite, since the TurtleScript parser can only parse
TurtleScript.
Add asm.js parsing benchmarks.