Add python 2.7 installation and set 2.7 as default python.

pym/cl_assemble.py

@@ -622,8 +622,10 @@ class cl_assemble(color_print):
 
         # stage3 contains python-2.7 without USE="xml" need for layman
         emergePython = "USE='xml' emerge -1 python:2.7"
-        self.printMessageForTest(_("Installing %s")%"python")
+        self.printMessageForTest(_("Installing %s")%"python:2.7")
         self.runChroot(emergePython)
+        self.printMessageForTest(_("Set %s as default")%"python:2.7")
+        self.runChroot('eselect python set python2.7')
 
         self.printMessageForTest(_("Loading calculate overlay"))
         if filter(lambda x:"calculate" in x,self.runChroot("layman -l")):