Add plugin feature.
Support a MacOS X's NotificationCenter feature as plugin.
Bugfix: NotificationCenter support bug.
Fix: plugin must not use config singleton instance.
Changed plugin interface.
Add Dropbox plugin for IFTTT.
Bugfix: Can't use dot '.' character in the todo message.
Add SendMail plugin.
Fix documents for emacs and vim.
Add plugins document.
Bump version number.
Add TODO plugin picture.
Replace pictures.
Change required ruby version.
Bump version number.
Bugfix: pastehubGet and pastehubPost outputs verbose message.
        This verbose message wrong for Emacs lisp and vim script.
Merge branch 'sendmail_plugin' of github.com:kiyoka/pastehub into sendmail_plugin