Merge pull request #408 from jcinis/master

dunst: notification muting moved to new dunstctl command

i3blocks-contrib will now follow the release schedule and have

corresponding version numbers to i3blocks. An i3blocks-contrib release
sharing the major and minor version numbers should work with the
i3blocks of the corresponding major and minor version numbers.
Patch numbers are not required for compatibility, but typically patches
are made to fix bugs, so it is always suggested to use the highest
available version.

Releases will be signed with

    6E59B8E5A268E206A086329E507E1F837C14FFA9

This is a pre-release tag for historical purposes.