* Proof of concept treating env vars as Values
* Refactor env var collection and method name
* Remove unnecessary pub
* Move env translations into a new file
* Fix LS_COLORS to support any Value
* Fix spans during env var translation
* Add span to env var in cd
* Improve error diagnostics
* Fix non-string env vars failing string conversion
* Make PROMPT_COMMAND a Block instead of String
* Record host env vars to a fake file
This will give spans to env vars that would otherwise be without one.
Makes errors less confusing.
* Add 'env' command to list env vars
It will list also their values translated to strings
* Sort env command by name; Add env var type
* Remove obsolete test
* option to replace command same name
* moved order of custom value declarations
* arranged dataframe folders and objects
* sort help commands by name
* added dtypes function for debugging
* corrected name for dataframe commands
* command names using function
* custom value trait
* functions for custom value trait
* custom trait behind flag
* open dataframe command
* command to-df for basic types
* follow path for dataframe
* dataframe operations
* dataframe not default feature
* custom as default feature
* corrected examples in command