Added IDisabledTrait & UpgradableTrait with upgrade levels support

	IDisabledTrait for identifying (and filtering) disabled traits
	UpgradableTrait provides an abstract base for enabling trait
		by upgrade level(s)
	Added IDisabledTrait support to GlobalButtonOrderGenerator
Changed UpgradeMinLevel => UpgradeMinEnableLevel & UpgradeMaxLevel => UpgradeMaxAcceptLevel and added UpgradeMaxLevelDisables.

UpgradeMaxLevelDisables will allow stat type upgrades based on UpgradableTrait to have UpgradeMaxAcceptLevel without being disabled.