use ipython layout similar to NSLS-II/CSX

[prjemian]

The CSX beam line at NSLS-II uses bluesky. The structure and layout of its ipython startup directory is different than ours.

APS XPCS layout

startup/
    00-0-checks.py
    00-logging.py
    00-startup-jup.py
    00-startup.py
    01-databroker.py
    02-pyepics.py
    09-imports.py
    09-overrides.py
    10-devices.py
    11-device-overrides.py
    15-spec-config.py
    20-detectors.py
    21-signals.py
    26-lambda.py
    26-rigaku.py
    35-DM-support.py
    50-controls.py
    60-metadata.py
    80-callbacks.py

NSLS-II CSX layout

startup/
    00-nsls2-tools.py
    csx1
        analysis
            __init__.py
        devices
            __init__.py
            areadetector.py
            devices.py
            eps.py
            epu.py
            lakeshore.py
            optics.py
            scaler.py
            stats_plugin.py
        plans
            __init__.py
            dark_ff.py
            nanop.py
            qplans.py
            xpcs.py
        startup
            __init__.py
            accelerator.py
            detectors.py
            endstation.py
            optics.py
            settings.py
            startup.py
            suspenders.py
            tardis.py

The instrument scientist reports this is much easier to understand and manage.

[prjemian]

The new directory for staff-created code (#145) could be moved as a new subdirectory of instrument.

[prjemian]

The first commits are to start using logger under the new layout. Complete the rest of this work in a branch once the diagnostic work is completed tomorrow.

[prjemian]

The support in 50-controls will go into various modules under instrument.plans.

[prjemian]

Tested the startup as part of #151. Successful. Can we spot check a few items?