Fixed "not so nice sites link" + some changes.
It still needs better structure because now its mixure of:
- dead projects from 1990
- not very valuable hobby projects without any support, documentation etc.
- used and active projects (Castle, SDL, SFML..)
Done:
ZenGL is game engine not framework - fixed
SDL/SDL2 merge in 1 link - fixed
Added description in framework section, fixed and added links
GameMaker: Studio link 100% does not belong there