Big refactor v0.30

All test pass, except for the TestConfig suite, which is not too critical as the
plan for this version onwards is to avoid configuration as much as possible.

examples/programmatic/programmatic_sim.py

@@ -1,7 +1,7 @@
 """
 Example of a fully programmatic simulation, without definition files.
 """
-from soil import Simulation, agents
+from soil import Simulation, Environment, agents
 from networkx import Graph
 import logging
 
@@ -25,23 +25,18 @@ class MyAgent(agents.FSM):
             self.info("This runs 2/10 times on average")
 
 
+class ProgrammaticEnv(Environment):
+
+    def init(self):
+        self.create_network(generator=mygenerator)
+        self.populate_network(agent_class=MyAgent)
+        self.add_agent_reporter('times_run')
+
+
 simulation = Simulation(
     name="Programmatic",
-    model_params={
-        'topology': {
-            'params': {
-                'generator': mygenerator
-            },
-        },
-        'agents': {
-            'distribution': [{
-                'agent_class': MyAgent,
-                'topology': True,
-            }]
-        }
-    },
+    model=ProgrammaticEnv,
     seed='Program',
-    agent_reporters={'times_run': 'times_run'},
     num_trials=1,
     max_time=100,
     dry_run=True,