Store list of previously open projects only in kicad.json
Keep all management of open projects in SETTINGS_MANAGER
Also add kicadSettings() for convenience
CHANGED: Cvpcb fpviewer and the pcbnew fpviewer no longer have an options dialog
ADDED: Add a side toolbar to the pcbnew footprint viewer (and the measure tool)
This also cleans up some of the settings structs in the viewers, since
it was somewhat confusing before.
Fixes https://gitlab.com/kicad/code/kicad/issues/2205
CHANGED: Settings are now stored in versioned sub-directories
ADDED: First-run dialog for migrating settings from a previous version
CHANGED: Settings are now stored as JSON files instead of wxConfig-style INI files
CHANGED: Color settings are now all stored in a separate settings file
CHANGED: The symbol editor and footprint editor now have their own settings files
CHANGED: Color settings are no longer exposed through BOARD object
CHANGED: Page layout editor now uses Eeschema's color scheme
Settings are now managed through a central SETTINGS_MANAGER held by PGM_BASE.
Existing settings will be migrated from the wxConfig format on first run of each application.
Per-application settings are now stored in one class for each application.