v0.4.0

This is a major update with fixes, new stuff, and an ABI break (as such, sover bump)

New stuff

• memory: Added UniquePointer

Fixes

• animation: don't fire update events if the avar is not being animated

MRs

• animations: fix adding/removing vars during ::tick by @PaideiaDilemma in #35
• fix CRegion::scale using x scale as y scale by @outfoxxed in #39
• animation: add virtual dtor to AnimationManager by @PaideiaDilemma in #31

Full Changelog: v0.3.3...v0.4.0