Gave a uniform structure to all com_users  views based on the default_login view

- Gave a uniform structure to all views based on the default_login view.
- All <forms> have been given a "well" class and the "well" class have
been removed from <fieldsets> when there was one.
- Put all buttons and inputs inside a <div class="control-group"> + <div
class="control"> hierarchy
- Removed id="user-registration" from <forms> not really pertaining user
registration
- Removed the space before <?php echo $this->pageclass_sfx?> in the
following views templates:
\components\com_users\views\login\tmpl\default_login.php
\components\com_users\views\login\tmpl\default_logout.php
\components\com_users\views\profile\tmpl\default.php
\components\com_users\views\remind\tmpl\default.php
\components\com_users\views\reset\tmpl\default.php