add schema for linux smelter arguments/flags

Signed-off-by: Alex Suraci <asuraci@pivotallabs.com>
add validation for smelter flag presence

Signed-off-by: Alex Suraci <asuraci@pivotallabs.com>
Follow the new rules of MaintainNode, a status channel

FakeBBS follows the same rules
Presence is now presence and PresenceInterface is now Presence