Patch to OOH´s form.php

Hi there, I´ve noticed that the opening tag for a form generated by HTML_OOH_Form lacks the "enctype" attribute when using fileupload elements. This way, uploaded files are never sent correctly by the browser. A small patch is included - I´ve added a new property that contains a list of all elements that require the "enctype" attribute to be set. In the addElement() method, this list is being checked and if the current element matches one out of that list, a flag is being set that tells getStart() to put the attribute into the form tag. Ironically, the flag has always been there, but was never set. Regards, Markus -- Markus Wolff <wolff@21st.de>