[#3103] Use helper for version instead of context

Instead of adding the ckan version as a value on `c`, this commit adds a
new template helper that returns `ckan.__version__`.

ckan/lib/base.py

@@ -197,7 +197,6 @@ class BaseController(WSGIController):
 
     def __before__(self, action, **params):
         c.__timer = time.time()
-        c.__version__ = ckan.__version__
         app_globals.app_globals._check_uptodate()
 
         self._identify_user()

ckan/lib/helpers.py

@@ -30,8 +30,8 @@
 from routes import redirect_to as _redirect_to
 from routes import url_for as _routes_default_url_for
 import i18n
-import ckan.exceptions
 
+import ckan.exceptions
 import ckan.lib.fanstatic_resources as fanstatic_resources
 import ckan.model as model
 import ckan.lib.formatters as formatters
@@ -41,6 +41,7 @@
 import ckan.lib.uploader as uploader
 import ckan.authz as authz
 import ckan.plugins as p
+import ckan
 
 from ckan.common import _, ungettext, g, c, request, session, json
 
@@ -364,6 +365,12 @@ def lang():
     return request.environ.get('CKAN_LANG')
 
 
+@core_helper
+def ckan_version():
+    '''Return CKAN version'''
+    return ckan.__version__
+
+
 @core_helper
 def lang_native_name(lang=None):
     ''' Return the langage name currently used in it's localised form

ckan/templates/base.html

@@ -26,7 +26,7 @@
     #}
     {%- block meta -%}
       <meta charset="utf-8" />
-      {% block meta_generator %}<meta name="generator" content="ckan {{ c.__version__ }}" />{% endblock %}
+      {% block meta_generator %}<meta name="generator" content="ckan {{ h.ckan_version() }}" />{% endblock %}
       {% block meta_viewport %}<meta name="viewport" content="width=device-width, initial-scale=1.0">{% endblock %}
     {%- endblock -%}