Allow `node.create` without the `component` parameter.
Allow `node.delete` by name as well as by reference.
Don't include messages following the current action in `kernel.getState.

In the queue returned by `kernel.getState`, exclude reflector messages
sent after the currently-executing action. These messages represent
external actions from the future and should not be included in the
replication state.

This is complementary with the queue handling in `kernel.setState`
which includes messages received after the currently-executing action
with actions from the received queue.
Accept reflector messages applying to non-existent nodes without error.

Using the view interface to the kernel, clients may generate actions
that apply to nodes deleted before the view action passes through the
reflector and eventually executes.

This commit omits execution for these actions and logs a debug-level
message. Similar cases with deleted properties, methods, or events are
not handled here.