This update replaces the existing uses of unique pointer creation with
the C++14 std::make_unique call that provides proper memory release in
event of an exception.
- support for background color setting
- removed several global config settings (such as g_Drc_On)
- wrapped most of global config settings in PCB_GENERAL_SETTINGS class
- reorganized PCB general options dialog to clearly mark which options concern only the legacy canvas
- new GAL feature for legacy users: double-click (or E) to change track width available as an option.
Fixes: lp:1530543
* https://bugs.launchpad.net/kicad/+bug/1530543
Fixes: lp:1707145
* https://bugs.launchpad.net/kicad/+bug/1707145
Wayne Stambaugh
Seth Hillbrand
Tomasz Włostowski
Maciej Suminski
decimad