As discussed with Ralf Schlatterbeck we should add the tracker 
initialization to the init function of the class RoundupDispatcher. 
Otherwise compilation of TAL templates and loading of python modules 
and libraries happends during the first request to Roundup.

This issue poped up during experimentation with pre-loading and lazy 
loading of WSGI processes with Apache. With this patch the request time 
for a rest api call from the first request dropped down from 2 seconds 
to 450ms.

diff --git a/roundup/cgi/wsgi_handler.py b/roundup/cgi/wsgi_handler.py
index 767221ac..ef4547a1 100644
--- a/roundup/cgi/wsgi_handler.py
+++ b/roundup/cgi/wsgi_handler.py
@@ -84,6 +84,9 @@ class RequestDispatcher(object):
                 tracker_home=home)
         else:
             self.translator = None
+        # trigger pre-loading of imports and templates
+        with self.get_tracker():
+            pass
 
     def __call__(self, environ, start_response):
         """Initialize with `apache.Request` object"""