This is almost certainly the correct default for Dokku. While it's a BC break and might cause an increase in memory usage, the api is mostly internal and therefore this is safe to use.
This changes restarts to drop the 'release' part that currently gets triggered, which also helps reduce the possibility that a new image layer will be added due to predeploy deploy triggers.
Note that the old method essentially halfway-rebuilt the app (which was what added the extra layer). This refactor removes that, which is a bc-break.
Additionally, scaling processes will result in deploying _only_ restarting the processes being scaled.
Closes#2184
