As part of the Grand Language Cleanup, a few examples in the tutorial
could be simplified:
* The --init-- function of the defclass example does not need an
explicit None anymore.
* The apply example in the Hy<->Python interop section can use a
keyword instead of a string in the last part.
This perhaps closes#971.
Signed-off-by: Csilla Nagyne Martinak <csilla@csillger.hu>
acd98bb79e