Primary change is to replace most control/window borders with
AUI pane borders. We implement our own AUI border drawing
routine which avoids the ugly one-pixel white frames around
dark canvasses.
Also increases the signal-to-noise ratio of all the pane
creation code in the various frames.
This allows it to participate in Kiway things such as updating
language or common settings.
Fixes: lp:1779558
* https://bugs.launchpad.net/kicad/+bug/1779558
(cherry picked from commit b3f8478)
KiCad read incorrect value for window position and it's size at very
first launch, which results in invisble/inaccessible window on Mac OSX.
Set correct default values for these settings fixes this issue.
And fix a typo in comment.