[PyQt] Displaying examples descriptions in qtdemo

[Dmitry Shachnev]

Hi,

I've noticed two bugs in qtdemo's MenuManager which make it not show
examples descriptions with this error:
"Could not load description. Ensure that the documentation for Qt is built."

First, helpRootUrl is always an empty string. Here on Debian it should
be "/usr/share/qt5/doc/MODULE/", where MODULE is, for example,
"qtwidgets" or "qtgui".

Then, getResource() always returns an empty QByteArray. Looks like
this is not implemented yet?

P.S. Thanks for all your hard work on PyQt!

--
Dmitry Shachnev