First pass at operational mode support for node states.
Operational mode (op_mode in the database) affects the state diagram and timeouts for a node. Modes planned so far are: NORMAL - Normal operation DELAYING - Acting as a delay node UNKNOWNOS - Running an OS that does not report its state (OSKit kernels, etc.) RELOADING - Disk reloading stated now responds to to TBNODEOPMODE events, and sets database state accordingly. The set of state timeouts and valid state transitions are affected by a node's operational mode. The nodes table now stores information about operational modes, and the state_transitions and state_timeouts tables include the operational mode in addition to states. Next step will be to get the appropriate programs to send TBNODEOPMODE events.