Find Nearest Point on Spline Feature!

• Added FindNearestPointOnSpline feature and sample project.
• Added "Extensions class" to support spriteBatch overloads with additional drawing capabilities.
• Added a test Transform in the TransformControl to have a dummy transform for additional user interaction in the sample projects.
• It's now possible to adjust the accuracy of the FindNearestPoint function from within the sample control.
• The GitHub-Release rar-file now containing not only the lib binaries but also the editor and sample projects - already pre-compiled, so that the user can directly start and run the samples or the editor; **no compilation needed! **