action/import: Add add process-level lock for linked clone creation
action/import: Add add process-level lock for linked clone creation

Fixes GH-206

KillerDesigner/vagrant-parallels,legal90/vagrant-parallels,Parallels/vagrant-parallels,Parallels/vagrant-parallels,legal90/vagrant-parallels,KillerDesigner/vagrant-parallels,legal90/vagrant-parallels,Parallels/vagrant-parallels,KillerDesigner/vagrant-parallels