#5 Builds fails with Qt5

[B Thomas]

OpenHantek fails to build with Qt5. Only a few small changes are required to make it build
1) Add printsupport in QT build configuration variable
2) Replace selectedFilter by selectedNameFilter in QFileDialog
3) Remove PostScriptFormat from QPrinter or replace it by QNativeFormat

A patch to do this is attached. It has not been tested throughly and is only provided as a convienence.