Fixed: Wrong encoding in graphs (bug#8207).
Squashed commit of the following:

commit 1ebb70ddeded0bda890c8e213cca10e3b94035ef
Author: s7design <otrs@s7designcreative.com>
Date:   Wed Apr 9 17:07:39 2014 +0200

    http://bugs.otrs.org/show_bug.cgi?id=8207

    Added config items for defining font for legend and title in graphs