Reorganized site and blog views and helpers to use LazyView

This increases the speed of the site by not requiring the site and blog code to
be imported on every request - just those that are relevant. It also splits the
code into modules which are easier to work with.

i2p2www/helpers.py

@@ -1,6 +1,18 @@
 from math import ceil
 from werkzeug import import_string, cached_property
 
+########################
+# General helper methods
+
+def get_for_page(items, page, per_page):
+    from_item = (page-1)*per_page
+    to_item = page*per_page
+    return items[from_item:to_item]
+
+
+########################
+# General helper classes
+
 class LazyView(object):
     def __init__(self, import_name):
         self.__module__, self.__name__ = import_name.rsplit('.', 1)