First phase of SketchSolver refactoring

First phase of SketchSolver refactoring

1. SketchSolver now is a base library for all other solvers
2. Created SolveSpaceSolver library to use SolveSpace.
3. Implemented minimal set of constraints: Coincidence, Fixed
4. Constraints: Horizontal, Vertical, Parallel, Perpendicular
5. Constraints: Distance, Length
6. Correct multi-coincidence of points
7. Constraints: Angle, Equal, Tangent
8. Replace list of base constraints in SketchSolver_Constraint by a single constraint
9. Constraint Mirror
10. Fix problem in arc movement
11. Multi-Rotation and Multi-Translation constraints
12. Process parametric values
13. Problem with mirror of an arc
14. Update multi-coincidence processing (several coincident points placed on single feature)