Error handling for disk prompt in Fuel

Change-Id: Id16eef106844d4dfbc30cc459dfe4314b78675ad
Closes-Bug: #1248903
Virtualbox scripts require ifconfig

Added check for /sbin/ifconfig existence under Linux/MacOS
Added check for ipconfig under Windows/Cygwin

Change-Id: I81ec63d5141ece93fd0119d63f1c2ee430a4b1c8
Closes-Bug: #1265902
Refactor dhcp_checker spec to use pcap

Add libpcap and python-pcap to dhcp_checker package

Closes-Bug: #1247284

Change-Id: I4a3c054cc26b0741874e111bc89272a5dddffcdd
Merge "Virtualbox scripts require ifconfig"
Merge "Error handling for disk prompt in Fuel"
Merge "Refactor dhcp_checker spec to use pcap"
Ceph build tweaks. Do not merge.

Change-Id: If7f369078f5e1b559a2ec2aa9429f3759e037ba4