remote/client: make acquire/release operate on all RemotePlaces in env#1748

Bastian-Krause wants to merge 4 commits intolabgrid-project:masterlabgrid-project/labgrid:masterfrom

Bastian-Krause:bst/acquire-all-remoteplacesBastian-Krause/labgrid:bst/acquire-all-remoteplacesCopy head branch name to clipboard