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/GCode.hpp

@@ -1,6 +1,7 @@
 #ifndef slic3r_GCode_hpp_
 #define slic3r_GCode_hpp_
 
+#include "JumpPointSearch.hpp"
 #include "libslic3r.h"
 #include "ExPolygon.hpp"
 #include "GCodeWriter.hpp"
@@ -374,6 +375,7 @@ private:
     OozePrevention                      m_ooze_prevention;
     Wipe                                m_wipe;
     AvoidCrossingPerimeters             m_avoid_crossing_perimeters;
+    JPSPathFinder                       m_avoid_curled_filaments;
     bool                                m_enable_loop_clipping;
     // If enabled, the G-code generator will put following comments at the ends
     // of the G-code lines: _EXTRUDE_SET_SPEED, _WIPE, _BRIDGE_FAN_START, _BRIDGE_FAN_END