Fixes [Request] Add optional perimeter to raft #756
Fixes First support layer does not stick to bed #2101
New parameters raft_first_layer_density and raft_first_layer_expansion
to influence the 1st layer of raft or support.
Fixes Allow to disable raft under support structures. #3772
Fixes raft is larger than necessary #2568
Fixes Supports on the build plate should have a solid bottom interface for better adhesion #1165
Changed the 1st layer infill to rectilinear even for soluble materials.
Fixes first layer of support for multi filament support oddly spaced #1445
Fixes Full Soluble Materials interfacing into Models + Soluble material noise on Bed #684
1) All slicer's exceptions are now derived from Slic3r::Exception.
2) New exceptions are defined for slicing errors.
3) Exceptions are propagated to the Plater to show.
It remains to modify the slicing back-end to throw the new SlicingError
exceptions instead of std::runtime_error and to show the other exceptions
by a message dialog instead of a notification.
producing better shortest path estimate than the "closest next neighbor"
heuristics. The new greedy algorithm utilizes KD tree for closest
end point search, and builds a graph to detect loops.
PerimeterGenerator newly uses the optimized TSP algorithm.
ExtrusionEntity has been refactored / simplified.
Iterator loops replaced with C++11 loops.
Fixed clone() methods to return an ExtrusionEntity*.
PerimeterGenerator now uses move semantics on ExtrusionEntity a little
bit more.
