Remove the hook_entity_info_alter() too thanks to Berdir.

Remove dependency to 'encrypt' module and use form element 'value' to store values. Thanks Simon Georges (User #172312) for the tip !

Adding a better detection of the contact module and table to prevent errors when loading a page with an email field using the "contact form" formatter.

Removed drupal_render().
Better handling of forms.

Adding a views handler to override views_handler_field_user_mail and display the form using views_form() method.
Adding a formatter for the email field type, if you want to use it, you need the email module.