Add some documentation & screencasts, call for use cases.

I'm dropping this otherwise promising module because I never could figure out how to fill the "Controller field value mappping" area.
In good faith I suggest you to put some basic documentation somewhere for those people who could find your module fitting their needs.

seriously-- I know you want to add good docs and a screencast, but can you just provide a couple of example for what actually goes into the 'allowed values mapping' fieldset? I've even been reading the code and debugging with dpm, and I can't figure this out.

I'm simply trying to use values from a selected nodereference field to populate a couple of simple text fields, but nothing I put there works. And I can't even figure out where to place dpm statements to see what it's expecting.

I'll be happy to write it up and provide some examples in the form of a patch for the readme, but I need to figure out how to use it first, lol.

The "Controller field value mappping" (sic) field is set in the controlled field. These entries map controller field values to possible controlled field values.

As an example, in our case a power company sells power via various distributors. Each distributor covers certain postcodes but there are overlaps.

For the controller field we have a text field for entering a postcode and the controlled field is a select list of possible distributors for each postcode. The "Controller field value mappping" field has the following:

3000|dist1
3002|dist1,dist2,dist3
3003|dist2,dist3

So if someone types in "3003" in the postcode field, the Distributor select would list the options "dist2" and "dist3"

PHP isn't supported yet for this field: #1026648: PHP support for Controller field value mapppings

The "Allowed values list" is simply a list of all the distributors.

Doing some cleanup as there's a new version for D8/9 and D6 is no longer alive