clean up extension unit files on decommission
Review Request #212 - Created Sept. 14, 2015 and submitted
|mitr, nphilipp, sgallagh, twoerner|
Deployed databaseserver, checked that extension unit file paths are stored in role JSON file, decommissioned it again and checked that the files are installed, and removed again.
NB: This is only about extension units, the patch for the others is reviewed in #216.