Use booleans to create proxy for optional services

This patch adds boolean parameters to the load balancer manifest such
that optional service (neutron, heat_cfn, heat_cloudwatch) will only
have a proxy created when the associated boolean is set to true.
Always specify mode for frontend

This patch explicitly sets the mode parameter for every proxy the load
balancer manifest creates. This prevents warnings about using tcp mode
with the httplog option.
Create proxy for swift

This patch will create a proxy for swift-proxy on port 8080.
Merge pull request #78 from rohara/master

Use booleans to create proxy for optional services