Support for softGlue and softGlueZynq

[prjemian]

APS provides two FPGA boards collectively known as "soft glue" for use in EPICS.

• softGlue (for VME)
• softGlueZynq (standalone FPGA + IOC), docs

Provide support for each of these.

Thanks for the suggestion, Andrew Chuang, APS!

[prjemian]

There are many parts to this support. Each installation might only use a subset and not want to make connections to unused EPICS PVs. Consider how to modularize, maybe construct support with a factory function.

[prjemian]

modularization for each of the parts described in the GUI

consider support for saving and restoring circuits