Added sprite support

Done:
 - Added resource logic
 - Added parsing of sprite definitions
 - Added rendering of sprites

TODO:
 - Add dye support
 - Add hair support
 - Add race/base sprite support

Reviewed-by: bjorn.
Added support for race sprites

done:
- Moved sprite parsing into static function of spritereference
- Introduced RaceDB
- Added the race sprite to the BeingItem
TODO:
- Add proper race support
- Move race definitions into an own file
- Fix odd parsing of items.xml

Reviewed-by: bjorn.
Half implemented hair support

Next commit will be half rewrite so this one is not 100% done.

Reviewed-by: bjorn.
Replaced sprite handling with QML code

The sprites are no handeled in a listview which creates the SpriteItems based
on the introduced sprite model of each being

Reviewed-by: bjorn.
Added support for displaying npc sprites

Reviewed-by: bjorn.