Help: Add notes for topic 'vs14-generator'
FindQt4: Don't further process qmake if it does not belong to Qt4

If the only qmake that can be found belongs to Qt5 the find module
would otherwise still further interrogate it and issue diagnostics
which are specific to Qt4.
Merge topic 'vs14-generator' into next

f0e298ad Help: Add notes for topic 'vs14-generator'
Merge topic 'FindQt4-ignore-qt5' into next

567d4d8d FindQt4: Don't further process qmake if it does not belong to Qt4