Coverity (CIDs 22640, 22316) complained that some members weren't
initialized.  Although setters are provided for these members, we have
no guarantee that they're called, so initialize to sensible values.
Chose indefinite repeat (repeat count -1) rather than single-shot.

In the process, discovered each class's m_to was used only in the
constructor (my initial change removed even this use, leading to a
compiler warning, as error, on OSX); so removed from both classes.

Change-Id: Ibb88a6190f2d740f57c67c1d5ee8a7b03129c510
Reviewed-by: Eskil Abrahamsen Blomfeldt <eskil.abrahamsen-blomfeldt@qt.io>