Screenpath is overloaded

[slominskir]

Currently screenpath field often contains one of four things:

1. Absolute file system path to EDM file
2. Human instructions for navigating JMenu (using Unicode arrow characters)
3. On-the-fly (OTF) Screen Generator command
4. EDMRun command (optionally with macros)

Do we want to keep a single field, or should we break this into multiple fields? For example it may be useful for both Human JMenu instructions and programmatic path.

Note: Other things to consider include:

1. Read-only web view of EDM screens are available too, but at a URL, not filesystem path.
2. Some EDM screens are network mounted in various different places making path aliases or host-dependent.

[slominskir]

Using instance-level "screencommand"