Add better help text to scheduler options (3)
Add better help text to scheduler options (3)

The previous commit moved all the scheduler options to a central
location. This commit adds additional help text to those options.
Because of the large number of options, the improved help text will be
split into several patches; this is patch 3 of 7.

Blueprint centralize-config-options

Change-Id: Idc4f94cf7943992e8beb4a81642a9a24afdf4d8b

alaski/nova,mikalstill/nova,gooddata/openstack-nova,cernops/nova,gooddata/openstack-nova,NeCTAR-RC/nova,bigswitch/nova,mahak/nova,rajalokan/nova,sebrandon1/nova,cernops/nova,klmitch/nova,klmitch/nova,bigswitch/nova,vmturbo/nova,BeyondTheClouds/nova,hanlind/nova,Juniper/nova,rahulunair/nova,zhimin711/nova,alaski/nova,rajalokan/nova,CEG-FYP-OpenStack/scheduler,Juniper/nova,jianghuaw/nova,rahulunair/nova,mikalstill/nova,rahulunair/nova,CEG-FYP-OpenStack/scheduler,cloudbase/nova,vmturbo/nova,vmturbo/nova,Juniper/nova,klmitch/nova,rajalokan/nova,openstack/nova,cernops/nova,BeyondTheClouds/nova,gooddata/openstack-nova,cyx1231st/nova,mikalstill/nova,BeyondTheClouds/nova,hanlind/nova,cloudbase/nova,klmitch/nova,dims/nova,mahak/nova,cyx1231st/nova,openstack/nova,openstack/nova,gooddata/openstack-nova,jianghuaw/nova,sebrandon1/nova,cloudbase/nova,dims/nova,hanlind/nova,phenoxim/nova,Juniper/nova,vmturbo/nova,jianghuaw/nova,zhimin711/nova,jianghuaw/nova,NeCTAR-RC/nova,phenoxim/nova,mahak/nova,sebrandon1/nova,rajalokan/nova