Update README.md
Merge branch 'develop'

Merge in 4.0.1 release.
Merge branch 'master' of https://github.com/HarveyHunt/i3situation

Conflicts:
	README.md

Fixed README conflict
Added a message for when cmus isn't active. I have also noticed a bug that
means items don't appear on the bar in the order in which they were defined in
the config file. I know how to fix it and will write a fix later.
Added a cmus not running message and bumped to version 4.0.2.
Merge branch 'master' into develop

Merged back in 4.0.2 changes.