[CMake] FindQt4 doesn't provide plugin variables

[Mike McQuaid]

It would be good if FindQt4 looked for the various plugins that can be
installed with Qt and gave the path to them (both release and debug
versions) and searched using the various filenames that are possible.

I'd suggest providing variables like:
QT_SQLITE_PLUGIN_LIBRARY_RELEASE

In addition, it would be good if these variables pointed to the DLLs
on Windows, rather than the LIB files, as the plugins would only be
used for installation. Also, it would be even better if there was a
simplified way to install the plugins and know what directory they
should go to, as obviously GetPrerequisites cannot help with this.

I've created an initial patch here:
http://public.kitware.com/Bug/view.php?id=11145

I think this is another thing that will help in the deployment of Qt
applications using CPack.

-- 
Mike McQuaid
http://mikemcquaid.com