mostly harmless typo fixes, plus a sustainer test

 - Renamed "weignt" to "weight"
 - Fixed a table name in the fundraiser.install file.  Had the brackets left on.  Only affected simpletest because of table prefixing.
 - Split stuff from fundraiser.test and submission.test into a fundraiserTestHelper class.  The fundraiser.test tests will pass.  The submission.test tests fail because simpletest can't fill out the state field since it's dynamically generated.  Drupal will complain about an illegal choice being made.  I can't figure out how to make this work.  See the todo items in submission.test.
 - Add sustainer.test to create recurring orders, test the charge dates, extend the orders and test the new charge dates.