Fixed some documentation and callbacks/declarations

Removed hooks from documentation that aren't hooked any more.

Changed initiation code to OnScriptInit to ensure it initiates before
OnGameModeInit (common place for using SIF definition or creation
functions).
Major update to Item and Craft

Item:
Added "uname" property to ItemType. Unique names are designed to
identify the item through means other than just the ID (possibly for
loading from a file) or for commands that take an item name as a
parameter. This also changes the DefineItemType parameters by adding the
"uname" parameter just after the regular "name" parameter.

Craft:
Changed dialog handling to inline y_dialog for consistency.