When filtering, we update the width of the displayed column to ensure
the full text is visible to the user. Check is rough, based on line
width (doesn't completely account for differing char widths) but is
sufficient for the approximate difference
Fixes: lp:1815401
* https://bugs.launchpad.net/kicad/+bug/1815401
Fixes: lp:1788495
* https://bugs.launchpad.net/kicad/+bug/1788495
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.