Improve help text of crypto.py
Improve help text of crypto.py

Implements blueprint centralize-config-options-newton

Change-Id: I7ccfc68d8fbab72119a6409a6d7775430282f13c

Juniper/nova,mahak/nova,rahulunair/nova,cloudbase/nova,vmturbo/nova,openstack/nova,gooddata/openstack-nova,rajalokan/nova,mikalstill/nova,jianghuaw/nova,mikalstill/nova,cloudbase/nova,klmitch/nova,Juniper/nova,alaski/nova,hanlind/nova,phenoxim/nova,phenoxim/nova,rahulunair/nova,gooddata/openstack-nova,vmturbo/nova,klmitch/nova,jianghuaw/nova,Juniper/nova,vmturbo/nova,jianghuaw/nova,sebrandon1/nova,rajalokan/nova,vmturbo/nova,sebrandon1/nova,mahak/nova,openstack/nova,hanlind/nova,gooddata/openstack-nova,alaski/nova,rajalokan/nova,openstack/nova,klmitch/nova,jianghuaw/nova,rahulunair/nova,klmitch/nova,rajalokan/nova,mahak/nova,mikalstill/nova,cloudbase/nova,sebrandon1/nova,hanlind/nova,gooddata/openstack-nova,Juniper/nova