Remove collision from personal shields, pass/handle damage from unit instead.

Fixes #51.
Enable dynamic harbinger hitbox code.
Harbinger Shielding Fix
Remove old dynamic shieldsize code
Fix whitespace
Update UAS0401_unit.bp

Allows Tempest to built all Aoen hover units
Plug error when issue #14 happens.

Also refactor code and comments a bit.
Only do overspill when instigator is Entity

There are certain damage events, such as "force" from strats, that don't carry
over an entity as instigator. In these events, the the instigator is the
damageData the projectile instead.

Closes #14.
Merge pull request #30 from FAForever/fix-nil-instigator

Fix nil instigator
Merge pull request #4 from FAForever/fix-personal-shields

Fix personal shields
Merge pull request #28 from TheMak/develop

Update UAS0401_unit.bp