Pm jps path finding (#8)

New step - estimation of curling on both the model and the support extrusions.
Improvements in curled filament estimation algortihm
Implementation of Jump Point Search algorithm 
Use of JPS algorithm to avoid curled extrusions during travel moves in Gcode export

src/libslic3r/PrintConfig.cpp

@@ -399,6 +399,13 @@ void PrintConfigDef::init_fff_params()
 
     // Maximum extruder temperature, bumped to 1500 to support printing of glass.
     const int max_temp = 1500;
+    def = this->add("avoid_curled_filament_during_travels", coBool);
+    def->label = L("Avoid curled filament during travels");
+    def->tooltip = L("Plan travel moves such that the extruder avoids areas where filament may be curled up. "
+                   "This is mostly happening on steeper rounded overhangs and may cause crash or borken print. "
+                   "This feature slows down both the print and the G-code generation.");
+    def->mode = comExpert;
+    def->set_default_value(new ConfigOptionBool(false));
 
     def = this->add("avoid_crossing_perimeters", coBool);
     def->label = L("Avoid crossing perimeters");