We can simply enable CMAKE_AUTOUIC and let CMake take care of handling
the UI code generation for targets.
As part of letting CMake automatically handle the header file parsing,
we must not name includes with "ui_*" unless they're related to the
output of the Qt UIC compiler. Because of this, we need to rename
ui_settings, given it would conflict with this restriction.
Instead, we make a proper registry class and house it within the main
window, then pass it to whatever needs access to the loaded hotkeys.
This way, we avoid a global variable, and don't need to initialize a
std::map instance before the program can do anything.
Lioncash