- abstract class WipeTower and its descendant WipeTowerPrusaMM were merged into a single (non-abstract) WipeTower class
- all uses of WipeTower::xy struct were replaced by Eigen Vec2f (it is no longer necessary to be independent on libraries that PrusaSlicer uses)
- the WipeTowerPrusaMM.hpp/.cpp will be renamed in the next commit (hopefully it will retain its git history that way)
The priming extrusions were handled separately from the rest of the wipe tower toolchanges. In order to be able to use the logic from previous commit for them (custom toolchange gcodes etc), some unpleasant code shuffling was needed
This is a fix of a long standing bug, where an extrusion is incorrectly
drawn from the end of the last wipe move. Interestingly enough,
this bug is in Slic3r at least since 1.2.9, but lucky enough
it only occured for single perimeter, no infill prints with wipe after
retract enabled, and only if the two successive slices were discretized
exactly the same, which is quite unlikely.
