graphs: yesterday added, plot detail only once

Signed-off-by: Thilo Fromm <github@thilo-fromm.de>
track.sh: gap in graph when station is closed

Signed-off-by: Thilo Fromm <github@thilo-fromm.de>
track.sh: fix graph gap / newline bug

Signed-off-by: Thilo Fromm <github@thilo-fromm.de>
graphs: left margin decresaed

Signed-off-by: Thilo Fromm <github@thilo-fromm.de>