Adding fundraiser_encryptswap module to swap encryption from one key to another (6.x)

Initial commit of fundraiser_encryptswap module. Swaps encrypted donation data from one key to another using a Drush command. There is no frontend/admin UI.

HOW TO USE:

    drush fundraiser-encryptswap \
      --old-key={contents of the key file, or a new key} \
      --new-key={contents of the key file, or a new key} \
      [all | {specific order ID}] \
      --pretend

You pass in the old key and new key as command line options. The old key is the key the orders are currently encrypted with; the new key is what you're converting the order to use.

You can pass "all" to convert all Ubercart orders, or operate on a single order ID.

Pretend mode, if set, means that no changes will be saved to the database. Otherwise, changes will be saved to the database.