Enable mod_proxy to sit in front of TurboGears and pass along the

kerberos principal name
Add an identity an visit class to TurboGears that can handle the user
 without requiring a database
Update the UI to show the user correctly.
Note that this is currently disabled. It is hardcoded to always return the
 principal test@FREEIPA.ORG in proxyprovider.py
It doesn't handle an unauthorized request because that can never happen.

ipa-server/ipa-gui/setup.py

@@ -58,5 +58,11 @@ setup(
         # 'Framework :: TurboGears :: Widgets',
     ],
     test_suite = 'nose.collector',
+    entry_points = """
+    [turbogears.identity.provider]
+    proxyprovider = ipagui.proxyprovider:ProxyIdentityProvider
+    [turbogears.visit.manager]
+    proxyvisit = ipagui.proxyvisit:ProxyVisitManager
+    """,
     )