Use Proxima Nova font in input fields.
Registration and login form enclosed in <form> tag.

This enables to submit form with ENTER key.
Javascript API wrapper updated.

New methods: email_get, alias_get, email_add, alias_add, alias_delete.
Select primary_email_id when authenticated.
New method Alias::owns ().

The method is very similar to Alias::exists () but unlike the latter
one it takes user_id as a second parameter. This allows us to check
not only that the alias exists but is also a property of a specific user.

Method Alias::delete () requires a second parameter user_id. In theory
the parameter could be omitted as a call to Alias::delete () is always
preceeded by a call to Alias::owns (). In reality shit happens so consider
it a safety precaution.
Hostname configuration array.
FIX: check alias ownership.

Use Alias::owns () instead of Alias::exists ().

FIX: Alias::delete () requires a second parameter.
Expect and process hostname.

Alias name should be a concatenation of user's input and one of
the preconfigured hostnames.