Fixing the long-standing bugs with author implosion, cleaning up token descs. Last update before the D6 version.

Should now work properly when multiple ASIN fields are attached to a single node type (primary item versus related items, things like that).

Deleting an ASIN now works, and validation catches incorrect values. Previewing on dit forms still doesn't work, that will take some tinkering.

Initial checkin of the ASIN module -- adds an Amazon ASIN/ISBN CCK field type. Requires the Amazon Tools module.