Made Python testing more verbose by default

Avoid using the Boost.Test library wherever possible.


[SVN r24249]

libs/python

@@ -1 +1 @@
-Subproject commit bd985d67d889651a749c823848da6ee01532a8ec
+Subproject commit cac6d3e5acfbdfe5e503a670d5a818dc2faafb37