Nudge insert

[matthewrmshin]

By moving the logic to process the command queue to an earlier position
in the main loop.

Allow an inserted task to be released from the runahead pool so that it
is listed as a waiting task by the GUI. Previously, it would be listed
as a runahead task, and a nudge would be needed to release it to the
pool.

@hjoliver @benfitzpatrick please review.

[matthewrmshin]

Not sure how to create an automated test for this because as soon as we talk to the suite, it fixes itself. I tested the change with this suite:

[scheduling]
    [[special tasks]]
        exclude at start-up = t2
    [[dependencies]]
        graph = 't1 => t2'
[runtime]
    [[t1]]
        script = sleep 120
    [[t2]]
        script = true

1. Run the suite.
2. Start GUI.
3. Insert t2.1 via CLI or GUI.
4. Look at the change in the GUI.

On master, the task will have the runahead status (and will get itself filtered out by default).
On this branch, the task will have the waiting status.

Test battery passes in my environment.

[hjoliver]

Thanks for this - I had noticed it myself a while back but forgot to deal with it.

Review 1 - good, all tests pass.