Stronger Validation for Openstack.config.
Better handling of detecting and raising NullReferenceExceptions
Removal of dead code in a few places
Added ability for each ServiceProvider to supply a ServiceMap which translates his name for a CoreService to something we can work with.
Optimized code for dealing with Runspaces.
This change implements 2 separate use cases for Multi-Vendor support.
a. Initial Bootstrapping
b. Switch Providers
Change-Id: Ided462e5050214321e1ead50cf0498707d59128f
Partially-implements: blueprint implement-multiple-vendor-support
53dc8b3bf9