In Qt 4, we loaded resources through the QTextEdit or
QTextControl if they were the parent of the document.
Modularization for Qt 5 broke this, as we can't cast
the parent to a QTextEdit anymore.
The fix is to make the loadResource() methods in QTextControl
and QTextEdit invokable and discover and invoke them at
runtime on the parent object.
Task-number: QTBUG-25116
Change-Id: Iba04bc16849b0c5ddcd275f12d1a386a8fe591bf
Reviewed-by: Girish Ramakrishnan <girish.1.ramakrishnan@nokia.com>
ac300a166f