Update FAQ about unsupported Python versions

Thanks to @ThomasWaldmann for the original patch. His fork is gone so I
can't apply the original commits.

docs/faq.rst

@@ -147,15 +147,21 @@ work in production environments::
 Credit for this snippet goes to `Thomas Johansson
 <http://stackoverflow.com/questions/3086091/debug-jinja2-in-google-app-engine/3694434#3694434>`_
 
-Why is there no Python 2.3 support?
------------------------------------
+Why is there no Python 2.3/2.4/2.5/3.1/3.2 support?
+---------------------------------------------------
 
 Python 2.3 is missing a lot of features that are used heavily in Jinja2.  This
 decision was made as with the upcoming Python 2.6 and 3.0 versions it becomes
 harder to maintain the code for older Python versions.  If you really need
 Python 2.3 support you either have to use `Jinja 1`_ or other templating
 engines that still support 2.3.
 
+Python 2.4/2.5/3.1/3.2 support was removed when we switched to supporting
+Python 2 and 3 by the same sourcecode (without using 2to3). It was required to
+drop support because only Python 2.6/2.7 and >=3.3 support byte and unicode
+literals in a way compatible to each other version. If you really need support
+for older Python 2 (or 3) versions, you can just use Jinja2 2.6.
+
 My Macros are overridden by something
 -------------------------------------