Some bugfixes for TrikStudio a8

+ swaped real and unreal update intervals;
+ wheels in TRIK robot picture moved to back;
+ 2D model is now again automaticly shown on interpretation start;
+ repaired draw line and circle blocks;
+ fixed linker`s floating segfault;
+ removed color enumerations; used QColor(QString) instead;
+ fixed incorrect 2D model robot`s rotation axis point;
+ fixed automatic centering on robot when returning it to far initial position;
+ corrected scene viewport position in examples;
+ fixed segfault when closing main window.