Manage accounts

This pull request handles the user accounts, that is, accounts that he can have such as bank accounts, cash, credit card or loan.

The currencies list that is being used is based on ISO-4217.

Account creation screens:

![2013 12 22_-_accounts](https://f.cloud.github.com/assets/168136/1798119/6886519c-6b2d-11e3-8a85-97644fed5461.png)

![2013 12 22_-_newaccount](https://f.cloud.github.com/assets/168136/1798120/68a17030-6b2d-11e3-8903-cd6cdc2ecaf9.png)

![2013 12 22_-_account](https://f.cloud.github.com/assets/168136/1798121/68b527f6-6b2d-11e3-9b3d-56810a11a353.png)