Update README.md

Added some options for secure cloud/backup services :)
Add NLNet Unbound to the list of DNS software

Unbound is just so dang good.
Adding softether VPN server
Adding sensu to monitoring section
Adding eucalyptus to cloud section
Adding metric collection and collectd
Adding missing bracket
Fixing the URL
Formatting
Adding new metrics applications
DRBD

Added DRBD to the list
Update README.md
  Added Slaughter.
Add BURP to Backup
Add git-annex assistant to cloud storage
Added ganeti to virtualization
Added oVirt to Virtualization
Merge pull request #1 from sarciszewski:patch-1
Merge pull request #22 from checkcheckzz/master

fix a typo
Merge pull request #7 from jimmypw/drbd

DRBD