spawn: multiple consoles from tests

[Ulrond]

Goal:

Add the ability to spawn more consoles, we should add the ability to the deviceManager to be able to spawn a new session (SSH session, internally)

The test therefore will then manage the release of the console.

newSession = self.dut.newSession("name")
...
pi5 = self.devices.getDevice( "pi5" )
pi5Session = pi5.newSession("MyPi5Session")
pi5Session.write("echo hello")

That means that the deviceManager can continue to hold a list of all the managed devices.

[Ulrond]

Spun off to Issue #104 to support integration of this