core: Add 'wait' parameter to vm.run_service function
core: Add 'wait' parameter to vm.run_service function

Sometimes it makes sense to "fire and forget" a service. For example
"qubes.InstallUpdatesGUI".

QubesOS/qubes-issues#1249

QubesOS/qubes-core-admin,woju/qubes-core-admin,woju/qubes-core-admin,marmarek/qubes-core-admin,QubesOS/qubes-core-admin,woju/qubes-core-admin,QubesOS/qubes-core-admin,woju/qubes-core-admin,marmarek/qubes-core-admin,marmarek/qubes-core-admin