Improved quota output
Improved quota output

This patch makes the output of quota show a bit more informative
by not setting a simple None to a non-existing quota, but not showing it
all together.

Kind of fixes bug #1078906
and also bug #1078089

Change-Id: Ic42837d218a80f37e0c6d56625c9804d076f444c

ntt-sic/python-novaclient,takeshineshiro/python-novaclient,ntt-sic/python-novaclient,takeshineshiro/python-novaclient,akash1808/python-novaclient,citrix-openstack-build/python-novaclient,citrix-openstack-build/python-novaclient,CCI-MOC/python-novaclient,metacloud/python-novaclient,akash1808/python-novaclient,JioCloud/python-novaclient,JioCloud/python-novaclient,Shihta/python-novaclient,mat128/python-novaclient,Shihta/python-novaclient,mat128/python-novaclient,metacloud/python-novaclient,guptaankita/python-novaclient,CCI-MOC/python-novaclient,guptaankita/python-novaclient