Update README.md

Reword to 'version'
#8: If a field's human-readable name differs from its machine name, then show both in the help text output
#8: Insure that cache-get and config-get help only shows output formats that are usable by these commands.
Fix #28. config-import and config-edit commands updated for D8 changes.
Get rid of --stdin in config-set and use '-' as the indicator, like cache-set.
Avoid a minor warning in config test.