Eeschema old format is line-terminated so the newlines in descriptions
will break the schematic file if saved.
Fixes: lp:1829707
* https://bugs.launchpad.net/kicad/+bug/1829707
(cherry picked from commit fb85612f81ccd05ef73a9365f17ee3ae3a1251f3)
Be more intelligent about sorting lib tree items. (Footprint
entries, for instance, come out of an already-sorted list.)
Don't recreate menus twice when laoding Footprint Editor.
More pervasive use of WX_FILENAME to avoid expensive calls to
wxFileName::SplitPath() and string concatenation.
For POSIX kernels do all the work on the file-system side so we
don't have to keep converting back and forth between encodings.
