Use jstranform instead of recast

This gains us a massive speedup, envify w/ recast takes almost 7 secs on my mba
when browserifying React codebase. While envify w/ jstransform takes this down
to 1.5 sec (pre-recast speed) and deliver the same advantages as recast
transform (preserves code formatting).
Semicolons

Sorry to be pedantic @andreypopp, just trying to keep things
consistent :)
1.2.0
Update contributors in README.md