Add new OpenGL context
Deleting files from old gl context
Adding exceptions

Small fixes in BezierCurve class method connected with exception. Small
fix of the main form
Adding shader class

Adding abstract class and realization
Fix shader system

Also some minor fixes in BezierCurve class
Now curve is rendered

First ignition of rendering
Merge pull request #1 from Alexey-Abakumkin/OpenGL-context

Open gl context