Add vmware support and external configuration for Vagrantfile

A different box needs to be specified for vmware as the ubuntu/trusty64
box repository does not provide a vmware box.

An external configuration file ("vagrant_config.rb") can be used to set
options for the vagrant environment.  By default tmate and devstack is
not being installed.  vagrant_config.rb.sample can be used as a basis
for configuring the environment.

Change-Id: I3948dea172943e25ae229840381f263c89bc9d55
Merge "Add vmware support and external configuration for Vagrantfile"