Added few changes for CLOUDSTACK-6316

1. Added pep8 changes, delete dc flag.
2. Now, delete dc works only if flag is set under config.
3. SSH, retries and delay were altered to reduce the time
for ssh connection

Signed-off-by: Santhosh Edukulla <Santhosh.Edukulla@citrix.com>
Signed-off-by: SrikanteswaraRao Talluri <talluri@apache.org>