* The EnvironmentDescription class describes an entire fullstack
environment (as opposed to the currently implemented host-only
descriptions). This will allow future patches to signify that a test
should set up an environment that supports tunneling, l2pop, QoS and
more.
* Now, most fullstack fixtures (config and process ones, at least),
expect both the EnvironmentDescription for the current test and the
HostDescription for the 'host' the config/process is on. This allows
for easier and most robust future changes, as now adding a new
parameter to one of the description objects doesn't mean adding that
argument to a number of other objects which are using it.
* Changed HostDescription's default argument of l3_agent to False, since
adding new configurations and defualting them to True forces the
author to go through ALL the tests and explicitly turn them on/off.
However, defaulting new configurations to False only requires
explicitly turning them on, which we ought to do anyway.
Change-Id: Ib2f12016ba4371bfda76c82e11d0794acc759955
7aa3b2eace