FC_USE_GTS not used since before:
1162aaea88 ("Remove references to gts and ode", 2012-07-05)
GTSAlgos.h and GTSAlgos.cpp removed in:
d1431f405c ("[Mesh] remove GTSAlgos", 2022-11-11)
MeshPy::coarsen() added not later than 2011 and never implemented.
Now all escaping required for the C++ code generation is done when the
.cpp/.h files are generated. Previously, only newlines were escaped
automatically. This was a) inconsistent and b) leaked c++ details into
the xml data.
In addition, the escaping is now done in one central place, harmonizing
the three previous implementations.
Pre-existing c++ escape sequences in the XML files have been replaced by
their literal equivalent so that the resulting python doc sting remains
unchanged.