This formats all copyright comments according to SPDX formatting guidelines.
Additionally, this resolves the remaining GPLv2 only licensed files by relicensing them to GPLv2.0-or-later.
Creates a new BasicSettings class in common/settings, and forces setting
a default and label for each setting that uses it in common/settings.
Moves defaults and labels from both frontends into common settings.
Creates a helper function in each frontend to facillitate reading the
settings now with the new default and label properties.
Settings::Setting is also now a subclass of Settings::BasicSetting. Also
adds documentation for both Setting and BasicSetting.
Narr the Reg