Empty array after mismatch fix

[defrag]

Quick fix for #13. Im not sure its perfect tho, but tests are passing.

[pskt]

I think that this fix will fail in situation like:
pattern:

{
'foo' => 'foo val',
'bar' => 'bar val'
}

Value:

{
'foo' => 'foo val'
}

Because you added failure only when value is empty

[defrag]

I added assertion for this also. It passed. @norzechowicz will look at this issue, cuz i am not to happy about this quick fix, but dont have time right now to rework it :)

[norberttech]

Closed in favor od #15