bmod_state: Saving and checking the status of the previous event.
Refactoring
bmod_state: required fields
bmod_state: state.add_event() adds another argument on_event(), instead of using the EXTRA.
bmod_state: host_name->host, service_name->service, needs bmod_const
Refactoring
bmod_state: fixed kwargs, added lock, removed some conditions
bmosd_state: fixed spaces
Merge pull request #31 from mdevaev/prev-state-2

Saving and checking the status of the previous event