createAction on transactions now redirects to indexAction instead of showAction

This makes more intuitive sense to me. Once I create a transaction, I'd
rather be taken back to the list of transactions.
Added memo field to LineItem
Added memo field for LineItem
When LineItem is created, account balance is updated

Created an event listener to update the account balance every time a line
item is created.

Created a startingBalance field in the Account form so it doesn't touch
the entity's balance field. The controller checks for the startingBalance
field and creates the transaction.
Allowed account balances to be updated dynamically with new line items