No longer emit trailing comma on object literals.

This was done because trailing commas in object literals are not accepted by ES3.

Fixes #271.
Print version number for --version.
Accept object literal commas in ES3, preserve in ES5.
Merge pull request #273 from Microsoft/es3HatesTrailingCommas

No longer emit trailing comma on object literals for ES3.
Moved error checking for command line options around.
Merge pull request #304 from Microsoft/likeaversion

Print version number for --version.
disallow statements between overloads
update LKG
Fixed error when parsing slashes in RegExp literals.

Basically we weren't recognizing that a slash can occur in a character class, so we were bailing out too early on code like `/[/]/`.

Fixes issue #318.
addressed CR feedback: changed error message
Merge pull request #317 from Microsoft/order_of_overloads

Disallow statements between overloads
fixed #75 and #92
added test for skipped node case
Merge pull request #320 from Microsoft/slashInCharClass

Fixed error when parsing slashes in RegExp literals.
Merge branch 'master' into ls
More changes to address code review comments