simpler area detector support

[prjemian]

Can the Device support for area detectors be made simpler?

The current implementation of ophyd.areadetector Devices produces many support requests, bug reports, and requires lots of user education. These are users who have used area detectors from other tools, such as SPEC.

• basic camera PVs
• control of only the desired plugins
• no need to provide Devices for intermediate plugins
• simpler for users to implement and troubleshoot
• user control of file name convention
• compliant with databroker external resource file model
• during setup/staging, do not write if PV already has new value

[prjemian]

This might be moved to M7

[prjemian]

Diamond Light Source is considering changes with ophyd v2 that will directly influence how area detectors are configured. This issue awaits those changes.