a-entity.js: removestate not working properly

[CodeRhymesLife]

a-entity's removestate expects is to return the index of the state it's searching for (or false if not found). Change 4699078 updated is to return true if the state is found rather than the state's index, which breaks removestate. Now, removestate does not remove the correct state if the state exists.

I think the fix here is to revert 4699078.

This issue effects the cursor's hover functionality, and likely other important scenarios that rely on state changes.

[ngokevin]

Not to revert that, but to have removeState look up the index.

Better to return true because index 0 should be a truthy case.

[dmarcos]

Fixed in #1115