docblock updates and two bugfixes

Splitting off the work from http://drupal.org/node/119845#comment-639138 (which is indeed the right way to proceed)

Here is phase 1 pulled out ot that combo-patch.
- Mostly just docblocks. Because I like docblocks.
- Extended and slightly formatted the help page.
- A bugfix for a typo in 'organisation/org
- Extra paranoia about the add-on library - the link was showing up when the card was unavailable.

So this should fold in OK. The other actual code stuff will pend on this.