添加放置单位技能

已经是不想再写这种简单无意义的教程了.................
powers.xml

	<power name="PowerPlaceUnit" type="TempUnit">
		<displaynameid>00450</displaynameid>
		<rolloverid>00451</rolloverid>
		<icon>art\Chino\ability_icon\question</icon>
		<minimapeventtime sendalertto="ally">1</minimapeventtime>
		<activetime>-1</activetime>
		<createunit quantity="12" radius="16" delay="0.0">Learicorn</createunit>
		<createunit quantity="4" radius="8" delay="0.0">GeorgeCrushington</createunit>
		<createunit quantity="1" radius="0" delay="0.0">MonsterTruckA</createunit>
		<placement forceonmap="1">LOSDontCare</placement>
		<startsoundset>PowerIceCream</startsoundset>
		<rangeindicatorprotoid radius="16.0" indicatorcount="16" speed="0.6">PowerRanger</rangeindicatorprotoid>
		<allowduringnorush>1</allowduringnorush>
		<alwaysaddtoplayer>1</alwaysaddtoplayer>
	</power>


上面三个语句分别是最外层半径16圆圈内放置12个利尔厉，内层半径8圆圈放置4个华盛顿雕像，中心点半径0圆圈放置安迪卡车。
<activetime>-1</activetime>为无限时间，也就是说放置后直到游戏结束都不会死亡，-1改成40就代表只能存活40秒，技能释放40秒后由此技能放置的单位全部死亡。


Abilities.xml:

		<ability>
			PowerPlaceUnit
			<rof>60</rof>
		</ability>