new: added templating system and examples with ``mustache`` template support for restructured text and markdown output format.
new: doc: added some information on path lookup scheme to find ``gitchangelog.rc`` configuration file.
new: added a ``mako`` output engine with standard ReSTructured text format for reference.
new: pkg: will launch ``./autogen.sh`` automatically. Even if called thanks to ``pip install git+https://github.com/vaab/gitchangelog``.