Squashing all commits for eway transaction logging and
suspect transaction identification.

- Switch from nose to pytest
- Switch to a new transaction log model
- Ensure setting order when order number is changed
- Add flag to indicate finished transactions
- Remove foreign key from transaction to order
- Add dashboard views for transactions
- Switch to status field for transaction
- Add check for dangling transactions
- Fix default values for migrations
- Add pagination to the transaction list
- Fix bankcard form for existing cards
- Add flag to checking suspicious transactions
- Fix flagging failed transactions as suspicious
- Make format strings python 2.6 compatible
- Fix obfuscation of bank details