Optimize Device Trackers

[Snuffy2]

Fixes #217
Makes #131 obsolete

[Snuffy2]

@alexdelprete feel free to merge these Optimize PRs if they look ok to you. But please hold off on a release. Once they are all merged, I'll put out another PR to do some final testing and cleanup that I couldn't do until all entities were redone.

[Snuffy2]

@alexdelprete there may be some issues with v0.3.3. There still needs to be some cleanup once all of the optimizations were merged. I'll try to get out a PR or 2 tonight.

If people are having issues with v0.3.3 then please have them go back to v0.3.2 for now.

[alexdelprete]

@alexdelprete feel free to merge these Optimize PRs if they look ok to you. But please hold off on a release. Once they are all merged, I'll put out another PR to do some final testing and cleanup that I couldn't do until all entities were redone.

I missed this comment last night, sorry about that. :(

Next time I'll make sure we're synced before releasing.