Added back setting of QT_QMAKE_EXECUTABLE in UseParaView.cmake

This was inadvertently removed in commit
eed7ccd3f7e804fed3864fcbe54fbd6958e63b41

Change-Id: I46ddec948e892cb507bf34549ae62b1b530e345e
Merge topic '15043_add_qmake_variable_back' into next

2a85f0c4 Added back setting of QT_QMAKE_EXECUTABLE in UseParaView.cmake
Fixed the base_proxyname for Representation proxy

Hat tip to B.W.H. van Beest <bwvb@xs4all.nl> for reporting the
error and proposing the fix.

Also, added cmake_minimum_required() command needed when plugin
is built outside ParaView.

Change-Id: I94ccba3bd2dae8384258c9501102f1d845115509
Made HiddenLinesRemovalPlugin work again

Change-Id: I47c4dfa56ca6c3411e47a253326889c33934d85c
Merge topic '15044_update_example_plugins' into next

0755d856 Made HiddenLinesRemovalPlugin work again
a7ab1831 Fixed the base_proxyname for Representation proxy