refactored most of the code
added support for Styles output (Markdown, HTML…)
added logging facilities
updated CLI commands
fixed a bug in changeset.unpack

Signed-off-by: Bernard `Guyzmo` Pratz <guyzmo+github@m0g.net>
updated gitignore

Signed-off-by: Bernard `Guyzmo` Pratz <guyzmo+github@m0g.net>
updated README

Signed-off-by: Bernard `Guyzmo` Pratz <guyzmo+github@m0g.net>