- Call print apply on all print within update_background_process
- Render multiple bed thumnail only when there is a reason to (by
requesting extra frame)
- Show status of the slicing process for each bed
- Add aggregated statistics
* 1. Remove all global include_directories.
* 2. Move 3d party dependencies from src to budled deps if possible.
* Unify and enforce one way of including headers:
e.g. #include "libslic3r/GCode.hpp" vs #include "GCode.hpp"
(always use the "libslic3r/GCode.hpp" option).
* Make all dependencies (also header only) a cmake target.
