Merge pull request #1046 from dalkon/master

combat events & more
Add 10 new item attributes

The following item attributes can now be customized for items: name,
article, pluralname, weight, attack, defense, extradefense, armor,
hitchance and shootrange.
Serialization for the new item attributes

This commit also cleans up the serialization code in other classes.
Fix Item.getAttribute for new attributes
Replace C-style casts with C++-style casts everywhere
Remove unnecessary if-statement
Add Lua function Item.hasAttribute