Add cost multiplier to UnitEquipmentItem

[ibboard]

The cost of an item is currently defined in the EquipmentItem as it is generally common to all units that are going to use it (e.g. all Ork characters pay 1pt for a Choppa).

There can be a small number of cases where a different price is paid, normally either nothing (e.g. in Warhammer 5th Edition a spear-armed unit had a free spear but the Champion had to buy a spear to match his unit) or half-price (e.g. in Warhammer 5th Edition Goblin infantry got equipment at half-price for being under 5pts, but champions paid full price).

The easiest way to define this would be with a "cost multiplier" in the unit's "UnitEquipmentItem".

[ibboard]

(In r118) Re #82 - Add cost multiplier to UnitEquipmentItem

• Add cost multiplier and rounding direction attributes to XSD

[ibboard]

(In r120) Re #82 - Add cost multiplier for equipment

• Fix enumeration name in Race XSD

[ibboard]

Attributes added so that they can be used from XML. Loading will be added in #50.

[ibboard]

(In r122) Re #82 - Add cost rounding

• Change values to match ones added in ​ibboard:r78
• Default to rounding up to the nearest half as this is least likely to cause invalid armies

no-open-ticket

[ibboard]

Mark released changes as released

[ibboard]

Mark released fixes as released using radio values

[ibboard]

Mark fix as released under a previous version