[#784] Update the support versions of Python and Postgres

doc/install-from-source.rst

@@ -31,8 +31,8 @@ wiki page for help):
 =====================  ===============================================
 Package                Description
 =====================  ===============================================
-Python                 `The Python programming language, v2.5-2.7 <http://www.python.org/getit/>`_
-PostgreSQL             `The PostgreSQL database system <http://www.postgresql.org/download/>`_
+Python                 `The Python programming language, v2.6 or 2.7 <http://www.python.org/getit/>`_
+PostgreSQL             `The PostgreSQL database system, v8.4 or newer <http://www.postgresql.org/download/>`_
 libpq                  `The C programmer's interface to PostgreSQL <http://www.postgresql.org/docs/8.1/static/libpq.html>`_
 pip                    `A tool for installing and managing Python packages <http://www.pip-installer.org>`_
 virtualenv             `The virtual Python environment builder <http://pypi.python.org/pypi/virtualenv>`_