WIP: Addressbook

Please, don't merge!

Related #351

This PR add support for create/delete alias for addresses on Send page.

* Modal popup to input the label and address.
* Create/Delete an array of label/addresses and store in LocalStorage. (One label to one address is allowed)
* Click on "label" to paste address on input field Address.
* Show list of label with its address on SendPage
* Mocha tests for create, get and delete.

TODO:

* Karma test to simulate input fields
* Send addresses to All copayers.