Log Message:
Update markdown2social to 0.3:

**Released on January 14th, 2016.**

* Issue 2: Added a manual page.

* Added support for a configuration file.  The default is to load
  `~/.config/markdown2social.conf` if it exists, and the path can be
  overridden via the `--config_file` flag.

* Added support to specify a set of "replacements" to apply to the post
  text after conversion.  This is useful, for example, to automatically
  turn bare references to external systems into links.