Update 3D-Print Toolbox Add-on

There are two things that prevent Slicer programs from properly creating gcode for 3D models when imported from Blender. Non-Manifold Edges and Inverted Normals/Faces. Most of the features needed to analyze and correct the mesh are in the Toolbox for Non-Manifold Edges. But to correct inverted faces the user has to go outside to turn on face orientation in one place, then go to another menu item to select the inverted faces and yet a third menu to flip the normals/faces. It would be nice to have the face orientation and correction included in the 3D-Print Toolbox. Additionally other programs like Windows 3D builder have better algorithms for correcting non-manifold edges. Please update the Blender algorithm for fixing non-manifold edges.