Move get_jinja_loader to init submodule.

mediagoblin/init/__init__.py

@@ -13,3 +13,21 @@
 #
 # You should have received a copy of the GNU Affero General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+import jinja2
+
+
+def get_jinja_loader(user_template_path=None):
+    """
+    Set up the Jinja template loaders, possibly allowing for user
+    overridden templates.
+
+    (In the future we may have another system for providing theming;
+    for now this is good enough.)
+    """
+    if user_template_path:
+        return jinja2.ChoiceLoader(
+            [jinja2.FileSystemLoader(user_template_path),
+             jinja2.PackageLoader('mediagoblin', 'templates')])
+    else:
+        return jinja2.PackageLoader('mediagoblin', 'templates')