- Settings is just a settings class, no UI involved, so
move to libcalamares where it can be used also from
system helpers.
- YAML utilities are useful at a lower level of the stack, too.
Now linking with -Wl,--no-undefined!
Moved find_package KF5 from the root CMakeLists.txt to the partitioning
module where it belongs. KF5 deps should be limited to plugins.
Lots of random fixage to make stuff link.
Removed CalamaresApplication reference from Settings.
Removed the use of AbstractPage, we don't need it right now.