Create upgrade script for financial_account table

Currently trunk.civiaccounts has an upgrade script for civicrm_contribution_type to civicrm_financial_account that makes these changes on an upgrade from civicrm 4.0 to civicrm 4.1. We are not going to be releasing this code as part of the 4.1 cycle, but as part of the 4.2 cycle. So we need to change what was previously there to make it so that it works for the correct upgrade (ie 4.1 -> 4.2 rather than 4.0 -> 4.1)

Make changes to upgrade from civicrm_contribution_type to civicrm_financial_account table and associated foreign key references to civicrm_contribution_type.id. The upgrade should be from 4.1 (ie trunk as of November 2011) to 4.2.

In addition, we will now be changing things to reflect the new civicrm_financial_type table. I believe there are 7 tables with fk's to financial_account.id in our branch that will need to be changed to an fk to financial_type.id.