[course-gridfunctionspace] Cleanup all examples

- YaspGrid constructors
- deprecated methods
[Example03] Adapted to latest changes (qkfem.hh, matrix backend)
[course-examples] Adapted examples 1 and 2 to the new matrix backend and Qk FEM
[course-examples] Adapted examples 4, 5 and 6 to new FEM and matrix handling
[course-examples] Adapt example 3 to new FEM and matrix handling
[course-examples] Adapted the rest of the examples and worked around a nasty bug concerning the pattern output in the instationary case

When setting up a Jacobian matrix after creating the instationary grid operator, the program will segfault, as OneStepMethod::apply() needs to be called to set the time step parameter class, which is null otherwise.

In order to print Jacobian pattern information this means:
(1) either do not try to construct the Jacobian in the driver until osm.apply() has been called or
(2) construct the Jacobian from the simple spatial gridoperator GO1, which does not have this problem
[Doc] Reflect changes in course-examples

Because now the new QkLocalFiniteElementMap is used throughout the course examples, we do not need separate drivers for Q1 and Q2 anymore. The howto now reflects this by just pointing to the merged *_Qk.hh header files.