Various message fixes

- Capitalize 'Internet' to make it consistent across Plinth.  See:
  https://en.wikipedia.org/wiki/Capitalization_of_%22Internet%22

- Other minor fixes

plinth/modules/dynamicdns/__init__.py

@@ -32,15 +32,15 @@ title = _('Dynamic DNS Client')
 
 description = [
     format_lazy(
-        _('If your internet provider changes your IP address periodically '
+        _('If your Internet provider changes your IP address periodically '
           '(i.e. every 24h), it may be hard for others to find you on the '
-          'internet. This will prevent others from finding services which are '
+          'Internet. This will prevent others from finding services which are '
           'provided by this {box_name}.'),
         box_name=_(cfg.box_name)),
 
     _('The solution is to assign a DNS name to your IP address and '
       'update the DNS name every time your IP is changed by your '
-      'internet provider. Dynamic DNS allows you to push your current '
+      'Internet provider. Dynamic DNS allows you to push your current '
       'public IP address to a '
       '<a href=\'http://gnudip2.sourceforge.net/\' target=\'_blank\'> '
       'GnuDIP</a> server. Afterwards, the server will assign your DNS name '

plinth/modules/dynamicdns/dynamicdns.py

@@ -176,13 +176,16 @@ class ConfigureForm(forms.Form):
             # Check if gnudip server or update URL is filled
             if not dynamicdns_update_url and not dynamicdns_server:
                 raise forms.ValidationError(
-                    _('Please provide update URL or a GnuDIP server'))
+                    _('Please provide an update URL or a GnuDIP server '
+                      'address'))
 
             if dynamicdns_server and not dynamicdns_user:
-                raise forms.ValidationError(_('Please provide GnuDIP username'))
+                raise forms.ValidationError(
+                    _('Please provide a GnuDIP username'))
 
             if dynamicdns_server and not dynamicdns_domain:
-                raise forms.ValidationError(_('Please provide GnuDIP domain'))
+                raise forms.ValidationError(
+                    _('Please provide a GnuDIP domain name'))
 
             # Check if a password was set before or a password is set now
             if dynamicdns_server and \

plinth/modules/dynamicdns/templates/dynamicdns_status.html

@@ -32,7 +32,7 @@
       {% endblocktrans %}
     {% else %}
       {% if no_nat %}
-        {% trans "Direct connection to the internet." %}
+        {% trans "Direct connection to the Internet." %}
       {% else %}
         {% blocktrans trimmed %}
           Behind NAT. This means that Dynamic DNS service will poll

plinth/modules/networks/networks.py

@@ -87,7 +87,7 @@ def show(request, uuid):
             device, connection_status['wireless']['ssid'])
 
     return TemplateResponse(request, 'connection_show.html',
-                            {'title': _('Show Connection Information'),
+                            {'title': _('Connection Information'),
                              'subsubmenu': subsubmenu,
                              'connection': connection_status,
                              'active_connection': active_connection_status,

plinth/modules/pagekite/templates/pagekite_standard_services.html

@@ -42,7 +42,7 @@
     <p>
       {% blocktrans trimmed %}
         Published services are accessible and attackable from the evil
-        internet.
+        Internet.
       {% endblocktrans %}
     </p>