Version 0.8.0

• Add a setting and a cli option to specify the gallery title (title and
  --title) (ref #91).
• Add a mailing list at Librelist (sigal at librelist.com).
• Add an option to specify the port to use for the serve command.
• Replace argh with click.
• Don't overwrite existing config file (with the init command).
• Don't fail if there are no pictures.
• Use plain css to simplify theme customizing (no more sass).
• Upgrade colorbox 1.5.13
• Upgrade galleria 1.4.2
• Use HTML5 output for Markdown.
• Allow to read additional data for images from markdown files.
• Use case insensitive check for file extensions (fix #99).
• Add a plugin system with blinker, and make plugins for copyright and adjust.
• Mention the irc channel on freenode and add travis notifications.
• Avoid failure if GPS tags contain zero values (fix #96).
• Remove output file when the ffmpeg process has been interrupted (ref #90).
• Fix thumbnail urls to always use slashes (ref #81).