Allow Spellvamp to work on self casted shields and heals

Giving shields and heals spell vamp would mean that the damages they soak is flat and are not factoring resistances (unlike damaging an enemy champion unless your doing true damage). As such the spell vamp % could be reduced to 75% for shields and 50% for heals. this is sort of arbitrary could be other way around too. Or to start out both at 50% or even 30% on pbe just to see how it goes.

Its not much: 50% of 20% (amount of spellvamp on wota or gunblade) of say 350 heal on warwick's q. so 35 extra health. Seems reasonable considering the cost of spellvamp. 

This would help make gunblade slightly more viable. Particularly on champions like udyr shen sion skarner nidalee who shouldn't adverse to itemize gunblade.

One of the premise behind this idea is that spellvamp is best on champions who does DMG on nearly all the spells in their kit. Cassiopeia kennen Vlad. kits with a defensive spell aren't getting gipped sort to speak.

note this would not apply on shields or heals received. only what youcast on yourself. its as if your treating it like a damage spell. whereas some champions would otherwise have a damage spell on either w,e,r... that benefit from spellvamp this would makeup for it.