Quoted empty strings are not recognized as valid arguments

[wolfmanx]

For an argument list with explicit empty strings, the tokenizer fails to produce the correct argv array.

For the following code:

args = tokenizeArgs('some "" empty "" args');
console.log(args);

the expected output is:

[ 'some', '', 'empty', '', 'args' ]

but the actual output is:

[ 'some', 'empty', 'args' ]

This is clearly not right.

I have already fixed this in my working directory. I can prepare a pull request, once the fate of pull request #5 is decided.