Do not rely on dbus auto-activation.

sugar/session/Makefile.am

@@ -0,0 +1,4 @@
+sugardir = $(pythondir)/sugar/session
+sugar_PYTHON =		\
+	__init__.py	\
+	session.py

sugar/session/session.py

@@ -0,0 +1,18 @@
+import os
+import sys
+
+import pygtk
+pygtk.require('2.0')
+import gtk
+
+from sugar.shell import shell
+
+def start():
+	shell.main()
+
+	activities = ['sugar/chat/chat', 'sugar/browser/browser']
+
+	for activity in activities:
+		os.spawnvp(os.P_NOWAIT, 'python', [ 'python', '-m', activity ])
+
+	gtk.main()