There are cases where you will want to keep vias that only connect to
one layer but still want to cleanup tracks. As distinct entities, they
are given their own checkboxes and actions
Fixes https://gitlab.com/kicad/code/kicad/issues/5019
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.
Fixes a few commit issues based on the std:: rework. Add an option to
delete tracks fully in pads and makes merge tracks smarter
Fixes: lp:1787190
* https://bugs.launchpad.net/kicad/+bug/1787190