implement osusers.forms.ChangeOsUserPasswordForm

- implement new form for password changes
- use osusers.forms.PASSWORD_MISMATCH_ERROR in osusers.admin
- add autogenerated documentation

gnuviechadmin/osusers/admin.py

@@ -6,6 +6,9 @@ from django import forms
 from django.utils.translation import ugettext as _
 from django.contrib import admin
 
+from .forms import (
+    PASSWORD_MISMATCH_ERROR
+)
 from .models import (
     AdditionalGroup,
     Group,
@@ -13,11 +16,6 @@ from .models import (
     User,
 )
 
-PASSWORD_MISMATCH_ERROR = _("Passwords don't match")
-"""
-Error message for non matching passwords.
-"""
-
 
 class AdditionalGroupInline(admin.TabularInline):
     """