Add a device_table parameters to Command::importTable() and
add_imported_dives(). The content of this table will be added
to the global device list (respectively removed on undo).
This is currently a no-op, as the parser doesn't yet fill
out the device table, but adds devices directly to the global
device table.
Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>