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.
Fixed small bug in attack core. warmup and cooldown was mixed
Fixed the atinit function

Previously each map had its own scope. They got merged now but the atinit
function was forgotten to adapt.
Fixed resistance calculation not damaging the damage handling
Hacked away the selection of attributes at char creation

All attributes are set to 5 for now
Made sure in-inventory trigger is called at pickup
Removed old warnings from chr_inv_change. They are handeled different now
[UGLY HACK] allows to prevent sending client information about inventory insert
Fixed reading skill from XML attack nodes

It was forgetting to actually set the Damage::skill member.
Fixed issues with removing attribute modifiers

* AttributeModifiersEffect::remove was not calling updateMod with the
  'value' parameter, causing it to have no effect at all for Stackable
  modifiers.

* The cached value of the changed modifier effect was not being
  recalculated when removing modifiers, because it started one layer too
  high (there's an inconsistency here: AttributeModifiersEffect::add
  updates this cached value while AttributeModifiersEffect::remove
  doesn't).
Fixed recalculation of base attributes
Fixed removing of unarmed attack when equipping other weapons
Fixed wrong error raising in lua.cpp
adjust experience curve.