Progress: exit prep work, reserve and implement "setting" in entries and exits, add...

Progress: exit prep work, reserve and implement "setting" in entries and exits, add option to "ready', and update documentation.

Add documentation, specifications, and basic structural changes for the "exit" files.

The "entry" and "exit" files now reserve "setting" for designating settings.
Currently, only "entry" supports a setting and that setting is "mode".

The "mode" setting designates how the entry program is intended to behave.
When operating as a "service", the controller program will wait indefinitely for commands (via the not yet implemented "control" program or "control" socket).
When operating as a "program", the controller program will immediately exit after completion.

The "ready" Entry Action now supports "wait".
When "wait" is provided, the "ready" operation will wait for all current asynchronous processes to complete before operating.

Update documentation and specifications, adding the "exit" files.
Cleanup the existing documentation and specifications, fixing wording.