1.3.6

Closes #18 by adding the "activate" concept: a beam can be enabled or not and this means that it exists or not. When we disable it in reality we are destroying it.
Now with "active" concept we can have a beam that is enabled but could not be active so is possible to turn it off and on and keeping all its info.
MATT integration has been moved to this new set of API since is more useful this behaviour