Make swift FnGetAtt fault tolerant and block less

head_container is now only called for required attributes
and will tolerate failure if there is an issue with the underlying
container.

This was preventing deleting of stacks with swift resources.

Possibly this is eligible for backporting to milestone-proposed.

Change-Id: I2f489126957f11924943955a7f63a2ebc45f1911
Fixes: bug #1160584
Don't assume a Parameter value is a str

Currently show_stack and list_stacks will fail for templates
which have a Number in the Parameters.

This should be considered for backport to milestone_proposed.

Change-Id: I1b20babf0998f7714f8bc7bf144e03ff1d7c0c91
Fixes: bug #1160653
heat engine : Autoscaling reload Loadbalancer correctly

Since the change implemented as part of bug #1136148 we no longer
wait for nova to create the instance before reloading the loadbalancer
which means we race nova assigning an IP to the instance and typically
the loadbalancer config ends up with the 0.0.0.0 default value
which the loadbalancer implementation uses when nova returns no IP.

This patch moves the LB reload into a separate function, which is called
after instances are active on group creation or adjustment

Since our loadbalancer is broken without this fix, this is a candidate
for backporting to grizzly milestone-proposed.

fixes bug #1160407

Change-Id: I50423883dead9a615aa79b8765d5480a9345686d
Merge "Don't assume a Parameter value is a str"
Merge "Make swift FnGetAtt fault tolerant and block less"