parse: "a[]=&a[]=b" returns { a: [ 'b' ] }

[spudly]

Current Behavior:

qs.parse('a[]=&a[]=b');
// => { a: [ 'b' ] }

Expected Behavior:

qs.parse('a[]=&a[]=b');
// => { a: [ '', 'b' ] }

Without brackets, it does what I want, but...

qs.parse('a=&a=b');
// => { a: [ '', 'b' ] }

...but that's not really correct either (#38) so I'm not sure I want to just get rid of the brackets (esp. because my client-side code also has to work with a php backend).