Possibility to use existing wrapper (parent) element

[lkrzyzanek]

wrapElement method always creates a new "wrapper" element around input.
In some situations it would be great to pass the wrapper element within options and just do initialization like copy all CSS etc.

My use case is that we uses "adaptive placeholders" which requires to have label exactly after input element. Something like this:

<div>
  <input>
  <label>
</div>

[lkrzyzanek]

This is what I meant: #51
(min version is not committed).