Performance problems around memory locking

[tbranyen]

In order to avoid accidentally free'ing pooled memory, we lock/protect virtual dom objects. This comes at a cost though since we need to constant check lengths and use indexOf which isn't very fast on super large arrays. Since we're dealing with potentially thousands of objects, we need to figure out a more efficient way to handle object pooling and clean up.

[tbranyen]

Resolved in #48