Adding customizable unit recall cost variables

Add customizable unit and unit_type recall_cost to
unit and unit_types includes header and lua tags
Defaults to -1 for checking if set or not
Implementing customizable unit recall costs

Implements the customizable unit recall costs and allows for proper
undoing of a recall.
Implementing menu and whiteboard changes for new recall_cost

Adding information into the menu for recalls about costs
highlighting under and over team costs
Whiteboard displaying the right cost for a unit
	(was hardcoded for team cost)