* Simplify some constructs from the Python-3 migration
* update copyright, since I did maintain the SCons build continuosly
* remove unused method from Buildhelper
Furthermore, the documentation page for our build system
https://lumiera.org/documentation/technical/build/SCons.html
has been reworked, to add a synopsis, some further background
information about the internal structure of SCons and about
the specific conventions and definitions used for Lumiera
- most notably the NOBUG logging flags have been renamed now
- but for the configuration, I'll stick to "GUI" for now,
since "Stage" would be bewildering for an occasional user
- in a similar vein, most documentation continues to refer to the GUI
a long standing TODO to document the actual start-up sequence, which
is implemented this way since a long time now. There was an unwritten
section in the "Linking and Application Structure", which seems the
apropriate place for this kind of intricate techincal details.
Last week, Benny Lyons was here on visit in munich and he was pondering
the idea of an experimental secondary build system, as a way to learn
more about the source structure of Lumiera. This reminded me to fill
some missing parts of the documentation. Possibly this is also the
right moment to land the GTK-3 transition?
