Remove typo in the example rrdcached socket documentation
plugins/df_abs: fix the multiple block device

The special devices like tmpfs or none can appear multiple times,
so we need to append the mount point.

Closes: D#712793
Merge branch 'fix/d/712793' into stable-2.0
gitignore: ignoring output dir sandbox/
Merge pull request #116 from steveschnepp/ignore-sandbox

gitignore: ignoring output dir sandbox/

Conflicts:
	.gitignore