Fix #590, #589.

Unified wording Calibre-Web
Replaced one table on admin page, deleted password column
Removed spaces on layout page
Removed uesless commit calls during db migration
Implementation of registering by email

cps/templates/register.html

@@ -7,10 +7,10 @@
       <label for="nickname">{{_('Username')}}</label>
       <input type="text" class="form-control" id="nickname" name="nickname" placeholder="{{_('Choose a username')}}" required>
     </div>
-    <div class="form-group required">
+    <!--div class="form-group required">
       <label for="password">{{_('Password')}}</label>
       <input type="password" class="form-control" id="password" name="password" placeholder="{{_('Choose a password')}}" required>
-    </div>
+    </div-->
     <div class="form-group required">
       <label for="email">{{_('Email address')}}</label>
       <input type="email" class="form-control" id="email" name="email" placeholder="{{_('Your email address')}}" required>