* Escaped newlines should also produce SyntaxError
* Fix multiline comment parsing and add tests
* Adapt makePredicate to handle \u2028 and \u2029
* Move up nlb check in regex so it's checked before any escape handling
* Change error messages to conform ecma standard
* Find_eol not recornizing \u2028 and \u2029 as line terminator
* Remove \u180e as it is removed in unicode 6.3.0 from the category zs
This should simplify and improve implementation, make it easier to
implement template strings, and keep master a bit more in sync with
harmony.
Previous implementation wasn't broken, though the loop gave me the
impression it could read infinite numbers and annoyed me a bit. It was
also slightly unnecessary because the lookup involved only 3 characters.
* Don't interpret strings with escaped content as directive
* Don't interpret strings after empty statement as directive
* Adapt output to prevent strings being represent as directive
* Introduce UGLIFY_DEBUG to allow internal testing like EXPECT_DIRECTIVE
