Idea: rmq.app.async and rmq.app.main

Idea:

``` ruby
def some_method
rmq.app.async do
load_something_that_takes_a_long_time
rmq.app.main do
update_the_ui
end
end
end
```

In RedPotion:

``` ruby
def some_method
app.async do
load_something_that_takes_a_long_time
app.main do
update_the_ui
end
end
end
```

Allow an optional queue name:

``` ruby
def some_method
app.async queue: "com.clearsightstudio.myapp" do

end
end
```

Also the ability to make `main` synchronous within the current context:

``` ruby
def some_method
app.async do
app.main sync: true do
end
# won't run this until the above finishes
end
end
```

Thoughts?

The issue identifies no implementation files, tests, or entry points. Start by locating the existing app.async and app.main behavior, then review the three comments for context. Done would require an agreed design and verified support for asynchronous work, optional queue names, and synchronous main execution.

Written by the indexing model from the issue text.