Change ballcatch keys to arrows because on Windows OSes, you do not have two events if you press the two shift keys at same time
penalty, cleanup removed uneeded .py file
missing-letter, major graphical improvements.
 Merge branch 'master' into 'master'

Master

Change ballcatch keys to arrows because on Windows OSes, you don't have 2 events when pressing both shift keys at same time (https://bugreports.qt-project.org/browse/QTBUG-36940)
Merge branch 'master' of git-next.kde.org:bruno.coudoin/gcompris