Add suport for form elements with a label without 'for' defined

[pjfsilva]

It seems from the code that this only supports labels when defined like so:

<input type="checkbox" name="a" id="delete-confirm44" class="styled"/>
<label for="delete-confirm44">label</label>

but it does not support a perfectly HTML valid label format of putting the input inside the label and not defining the 'for' like so:

<label>
<input type="checkbox" name="a" id="delete-confirm44" class="styled"/>
label text
</label>

Looking at the code this isn't supported since 'for' is required to make the connection between input and label but an alternative can be tested to get the parent of the input if that's a label. It's a bit more code but this would make it work on both HTML valid usages.

I can try to do a patch, is that something anyone else is interested?