Searchable index in audit trail table

Hello,

At the moment, the trail table userpoint_txn doesn't have any searchable field a part from the txn_id.
I am a module developer myself, and need such a field.
Find attached two patches to:

* Change the .install file, so that the database has a new field called "reference" which is 128 characters long and it's indexable

* Change userpoints.module so that it allows people to define a "reference".

Note that the API is compatible, since $reference is added right at the end in the API function:

function userpoints_userpointsapi($op, $points = 0, $uid = 0, $event = NULL, $description = NULL, $reference=NULL){

Bye!

Merc.