Remember application settings

[mboerwinkle]

Addresses #77. Noteworthy facets of this change:

• 'Autoreload' is now always enabled. I assume that since it is a persistent setting, it makes sense to be able to configure it even if no model is loaded.
• Canvas::view_perspective and ::view_orthogonal are now merged into a single function with the help of constants Canvas::P_PERSPECTIVE and ::P_ORTHOGRAPHIC. I had to touch this code to avoid a perspective-warp animation while loading from persisted settings.
• Organization name is now 'fstl-app'. This should make it easier for users to find their configurations, since this repo is no longer under mkeeter.
• 'Orthogonal'/'Orthographic' name split unified under 'Orthographic'.

Here is an example configuration file:

[General]
autoreload=false
drawAxes=true
drawMode=2
invertZoom=true
projection=orthographic
recentFiles=/home/martin/test.stl, /home/martin/test2.stl

Please let me know if you have any feedback.

[mboerwinkle]

Forgot about the window geometry component of the request - added a windowGeometry setting using the method found here https://doc.qt.io/qt-5/qwidget.html#saveGeometry. This setting updates on resize or move (as the actions occur, same as the other settings), as opposed to the example code, which updates on window close.

[DeveloperPaul123]

Also, sorry for the delay on getting back to this 😅