Fix: Use platform-independent keystrokes in tests.
Fix: Use platform-independent keystrokes in tests.

This makes Mac tests pass.

hlamer/qutepart,Aldenis2112/qutepart,andreikop/qutepart,Aldenis2112/qutepart,Aldenis2112/qutepart,hlamer/qutepart,andreikop/qutepart,hlamer/qutepart,hlamer/qutepart,hlamer/qutepart,andreikop/qutepart,andreikop/qutepart,andreikop/qutepart,andreikop/qutepart,Aldenis2112/qutepart,Aldenis2112/qutepart,andreikop/qutepart,Aldenis2112/qutepart,Aldenis2112/qutepart,Aldenis2112/qutepart,andreikop/qutepart,andreikop/qutepart,Aldenis2112/qutepart,hlamer/qutepart,hlamer/qutepart,hlamer/qutepart,Aldenis2112/qutepart,andreikop/qutepart,hlamer/qutepart,andreikop/qutepart,Aldenis2112/qutepart,hlamer/qutepart,hlamer/qutepart