no cleanup of element styles if element has been blocked with string

[StilgarBF]

If a element is blocked with a string-message and then unblocked, blockUI leaves position: static and zoom : 1 at the element.

Install saves some states of the blocked element to data('blockUI.history'). But that's not happening if msg is a string.

if (msg && typeof msg != 'string' && (msg.parentNode || msg.jquery)) {
...

Then function reset has no data to reset the previous state.