Full refactoring of classes.js.
- non-wriatbility of class properties ensure by freezing the objects after the data is loaded from XML
- documentation added to all members in classes.js
- all classes now have an own method to load their data from XML
- ParticleDescriptor class created to handle functionality needed for several other classes
- WeaponDescriptor and PropulsionDescriptor classes created to support equip parameters for the future
- ObjectView class moved from logic.js to classes.js
- other: all game folders can now be queried from one function