deleted: unnecessary header inclusions
added: an overload of to_string() which takes a Sphere object
updated: ConvexContainer
updated: General3DMesh

Refactored and added the following 4 member functions.
- GetVertexPositions()
- GetTriangleIndices() x 3
updated: ShapeDetector & ShapesExtractor

Added support for convex shape.
updated: General3DMesh
changed: some class names

Dropped the 'C' prefixes.
updated: ShapeDetector

Adjusted the tolerance in ShapeDetector::IsConvex(), etc.