Rename AutoAttack to Attack
Work on (Auto)Attack system.

During the implementation bjorn and I agreed to limit the number of attacks that
can be used in the same tick to one. This makes a lot of stuff easier and the
client cannot display two frames at the same time

Things done:
 - Implemented setting of attacks when equipping/unequipping items
 - Single place where the xml attack node is parsed
 - Finished attack logic
 - Unified the attack handling of monsters and characters
 - Added a global cooldown after attack use
   (not only for next use of same attack)
 - Removed the temponary attributes for the monster attack values
 - Priorities for all attacks
 - Rewrote the attack core:
  - Attacks now have this attributes:
   - warmup -> time a attack needs after starting it to actually deal the damage
   - cooldown -> time a attack needs after dealing damage before another attack
                 can be used
   - reuse -> time before the same attack can be used again

  - If no attack is performed at the moment the following is done:
   - make a list with all ready attacks
   - check for attack that has the necessarily range and highest priority
   - start this attack (inform client about it)
   - when warmup is finished -> trigger damage
   - when cooldown is finished -> allow to use other (or the same if reusetimer
                                  allows) attacks
TODO:
 - sync client with this to allow better timed animations
Added script binds for getting attack information

New binds:
- Damage:
 - id
 - skill
 - base
 - delta
 - cth
 - element
 - type
 - truestrike
 - range
- Attack:
 - priority
 - cooldown
 - warmup
 - global_cooldown
 - damage
 - on_attack
- MonsterClass:
 - attacks
- ItemClass:
 - attacks
Added Vulnerabilities for monsters

You can now actually use the already used node in the monsters.xml
Monsters can have different vulnerabillities against elements:
<vulnerabillity element="earth" factor="2.0" />
This will double damage of the element earth to this monster.