This adds a small KiCad logo in the top left of the Doxygen pages.
54px used as 55px is maximum recommended height for Doxygen logos.
For the main docs and the dev docs, this is easily done in the Doxyfile,
for the Python docs, as that is run from the binary dir, the source dir
is passed as an Environment variable.
Change the Doxyfile project name from KiCAD to KiCad. It doesn't look
very good when we don't get the project name capitalization correct.
Clean up trailing whitespace in some of the helper scripts and Doxyfile.
pcbnew.py + doxygen-xml files, and build .i files with docstrings,
those .i files are included back again to build a pcbnew.py with
extended documentation from C++, finally we take the final pcbnew.py
to build the doxygen-python documentation