Update tern - fixes #3606, #3605

Also update acorn, as latest tern needs the latest version of acorn.

Codehinting tests all pass, and performance does not seem to have degraded.
Update acorn and tern.

Acorn is now version 0.2 and tern is 0.1
Merge pull request #3623 from eztierney/update-tern

[JS Code Hints] Update tern - fixes #3606, #3605