Allow " (qoute) in hash string param

[bckfnn]

handlebars.js allow for escaping a quote with a backslash: (from handlebars.l)

  <mu>'"'("\\"["]|[^"])*'"'        { yytext = yytext.substr(1,yyleng-2).replace(/\\"/g,'"'); return 'STRING'; }

but if I try this template I get a compile error:

  {{#each a="1\"2"}}{{/each}}

[bckfnn]

This hack to Parser.java seem to work, but I'm a parboiled noob so there may be better solutions:

@Label("string")
Rule string(final Var<Object> value) {
    return Sequence(stringLiteral(), value.set(match().replace("\\\"", "\"")));
}

@Label("string")
Rule stringLiteral() {
    return Sequence('"',
            ZeroOrMore(
            FirstOf(
                    String("\\\""),
                    Sequence(TestNot(AnyOf("\"\r\n")), ANY))),
            '"');
}

[jknack]

Seems to be a valid solution, can you send a pull request?

I'll write a unit test later.

Thank you.