new abook_import_export

[root <ro...@ns...>]

This version has Jason Reeves link fix and changes the export so that it
separates fields by comas "," rather than the SquirrelMail internal pipe "|"
format.

As a side note. If anyone actually uses this and wants to see improvements to
it you might want to take over maintenance of it. I have personally never used
it, other than to test it. This plugin could probably benefit from being
maintained by someone who cares if it works.

If no-one steps up to maintain it I will continue to do so but won't attempt to
make changes or improvements unless a patch is sent.