remove processor models and basic facts from behavior
Addresses #48 (closed): The behavior folder / namespaces should be reserved for defining our trace-based semantics and remain as minimal as possible. The actual processor state definitions don't need to be there. Similarly, the basic facts about the behavioral model really constitute a form of analysis and hence should also not be behavior folder.
The new basic_facts folder in analysis/ should probably be cleaned up at at a later point when we have a better idea of the structure of model/ and analysis/ (e.g., the ideal_schedule.v file should probably not be there in the long term). However, for now this works and helps us to keep the trace-based semantics clean and minimal.
Any concerns that would speak against merging this?