Bug 6273: (follow-up) fix various issues

Bug 6273: (follow-up) fix various issues

This patch fixes various issues that prevented the account
type from being set correctly when recording SIP2 payments:

- the fixed fields in the fee paid message were not getting
  parsed correclty
- accountlines.accounttype is only five characters wide, so
  SIP2 payments are now records as 'Pay00', 'Pay02', etc. rather
  than 'Pay-00'.
- removed regression on bug 2546 and made the new payment types
  translatable

Signed-off-by: Galen Charlton <gmc@esilibrary.com>