Workaround for negative vals in total*Used in nova absolute_limits

Due to bug 1370867 there is a case where negative values are returned
in total*Used in absolute_limits. If it occurs, Horizon Overview page
cannot be displayed due to an error "cannot convert float infinity to
integer". This commit replaces negative values in total*Used with 0
for a workarond.

Conflicts:
	openstack_dashboard/test/api_tests/nova_tests.py

Change-Id: I606803bdff1d335cc9f92d67619ff82f356a5143
Closes-Bug: #1370869
(cherry picked from commit d49ad74e280f9b7d9397e951f12dc428f26821df)
Handle negative values in total*Used for Cinder absolute limits

In some cases negative values can be returned for resources currently
in use. When this occurs, the project overview page fails with an
error 500 due to an OverflowError, "cannot convert float infinity to
integer". Handle this case more gracefully.

Change-Id: Id1ad16eafdde906dc74bfafc7f72ea8d3bdcdc8f
Closes-Bug: #1386687
(cherry picked from commit 53c7dc022ed4e0d5d60fb344b3e8c94e3dfb7d43)
Merge "Workaround for negative vals in total*Used in nova absolute_limits" into stable/icehouse
Merge branch 'stable/icehouse' of https://github.com/openstack/horizon into stable/icehouse