Markus Holzer authored Feb 07, 2019 and Martin Bauer committed Apr 26, 2019

The communication of the ghost layers used to communicate just all
values in between one time step to make sure that everything is correct.
Furthermore the communication was only valid for pull stream steps.
The improved communication distinguishes automatically between pull and
push and communicates only values which are needed. With this improvement
it was possible to implement the EsoTwist streaming scheme.