Fix bookmark/gaschange setting for Ubuntu

On Ubuntu, new events have time zero. This is fixed by resetting
gc.rightx to maxtime at the end of plot function.

Signed-off-by: Miika Turkia <miika.turkia@gmail.com>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
Remove nonexisting member from header

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
Update tank model with custom tanks used in XML files

Fixes #377

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>