Speed up start/stop/cancel/status commands

[kriskbx]

gtt is looping through the frames directory right now. Instead of doing that I would like to introduce a status.json file in the config directory.

Additionally add a --force option (naming is WiP) that uses the old methodology and rewrites the status.json if something goes wrong. Using the old methodology after a given timeout (like every X hours) would be appreciated too.