More options for primitives to draw in CCDrawingPrimitives

Added the following primitives to CCDrawingPrimitives:
- void ccDrawSolidCircle( CGPoint center, float radius, NSUInteger segments);
- void ccDrawArc(CGPoint center, CGFloat r, CGFloat a, CGFloat arcLength, NSUInteger segs, BOOL drawLineToCenter);
- void ccDrawSolidArc(CGPoint center, CGFloat r, CGFloat a, CGFloat arcLength, NSUInteger segs);