Update QT samples

Dear Author,

OCCT Qt sample still relies on Qt3Support layer of Qt 4. Is it possible to build Qt 4.x without Qt3 support and correct the sample accordingly? There are not really a lot of changes required, mostly some signal/slot names need to be changed, corresponding Qt messages are printed in the console.

I believe now we must consider porting to Qt 5 rather than (or in addition to) 4.
See http://www.opencascade.org/org/forum/thread_25021

Remark on branch CR23459: please revert changes in samples/qt/Interface/src/Translate.cxx: instead if handling FSD_File by pointer (which would lead to memory leak), just remove 'static' before the declaration.

Please, review

No remarks, please test

Tested