Finally have an animation system

Took a break from working on the dialog tree (which I've simplified a lot, because I was going overboard with condition variables unnecessarily) and finally got around to building an animation system. It's pretty simple but it does everything I need for Strangers, and I built it to be generic enough to probably work well for a lot of things so hopefully I end up using it in several games! I was probably a bit overly optimistic in putting it in the common library, but oh well.

As part of this I also finally factored out track1's event queue into a more generic object that I can use everywhere.

Other new stuff in this build:

• The dialog boxes now have sound effects (as you can also hear in the above video)
• Dev tooling around making sure my dialog cvars are being used consistently, and a bunch of improvements to dialog coverage analysis
• Fixed a bunch of bugs in the profiler (although frankly Piefiller is kind of crap and I'll probably replace it with something purpose-specific)