Optional class specifying for input elements was added to password widget.
"Email" account field was made visible only when email differs from login.
`value` method allowing to get and set fields' values was added to form widget.
Account form initialization moved to dashboard object due to remove `store` references from the form.
Dashboard-constructing functions were changed to methods.
Account form was moved to account-form.js
Account view was moved to account-view.js
Convenient Backbone's `el` and `$el` shortcuts was used at `AccountView`.