improve implementation of vocabulary creation (SKOS etc)

[graybeal]

The vocabulary creation tool can be improved as follows:

1. Walk the user through what needs to be done a bit more explicitly
2. Use proper (BioPortal-compatible) SKOS format for content
3. Allow viewing of content in regular formats in addition to table format
4. Create documentation
5. Consider importing sheets that are in SKOSplay convert format.
6. Consider allowing viewing (not modifying…?) in table format (a la BioPortal) even if original wasn't created that way