Add support for using environment variables in process flow connectors.

In an application, we want the end user to be able to make a selection of documents and download these files accordingly. We use a process flow to make this happen. When a user selects a couple of documents they should be copied to the download or document directory of the end user that executes the process flow. However the current process flow connectors do not support environment variables, like %userprofile%\Documents or %temp%.

This would give us the opportunity to move files from a connected file share to the document folder of the end user.

This would be a nice extension, since it creates a user friendly experience for the end user.