added file for fiber_helper style stubs on the client
Test for observe ordering in minimongo on server.

Currently failing.  Test first wheeeee!
Minimongo now uses a queue to manage observes

What this means for the user is that now, both on the server and the client, if
you look at a minimongo-backed collection from an observe/observeChanges
callback, you'll see a consistent view of it -- you'll never see it in the
middle of an update, for instance.

Furthermore, server!minimongo no longer has stubs, just future waits or
callbacks, your choice.
Just don't provide stubs for collection methods on server; test.

Test is for insert on server-to-server DDP minimongo side.
Queue behavior v1, flush until mark
New queueing semantics for observe events

When modifications to a collection are nested inside observe events for the same
collection, previously we would just throw an error.  Now, instead, we schedule
the new observe events for after the currently scheduled events, and make sure
they all happen before the outer modification returns.

I think this is going to be the least-unexpected behavior, even if it is a
little difficult to explain at first blush.
Glasser diff review comments