Added German Translations (#406)

* Added German Translations

Translated using
https://docs.djangoproject.com/en/1.9/topics/i18n/translation/

Added language drop down menu's for base.html, registration & login
pages

Known issues:
* Translated items in whtracker>create signature remain translated when
posted
* No date/time localisation for Fleet/Structure timers

* Added time locale

Added date/time locale to
*Structure Timers
*Fleet Timers
*Fleet timer form datetimepicker.js

Fixed a bug where the bootstrap label didn't show up when making a
structure timer using the translated form

Missed some base.html translations

* Small translation error

Some obscure SRP strings went unnoticed for context review

* FAT & Fleet-up German Translations

+ a fix in settings.py.example

The only small thing not done is German Date/Time locale for Fleet-up

* Compiled de/django.po

stock/templates/registration/password_change_done.html

@@ -3,17 +3,17 @@
 {% load i18n static %}
 
 
-{% block title %}{% trans 'Password change' %}{% endblock %}
+{% block title %}{% trans 'Password Change' %}{% endblock %}
 
 {% block content %}
     <div class="col-lg-12">
-        <h1 class="page-header text-center">Change Password</h1>
+        <h1 class="page-header text-center">{% trans "Change Password" %}</h1>
 
         <div class="container-fluid">
             <div class="col-md-4 col-md-offset-4">
                 <div class="row">
                     <p class="text-center">
-                        Completed
+                        {% trans "Completed" %}
                     </p>
                 </div>
             </div>