CMIS support for file transfer.

Issue generated from Tuleap's migration script. Originally submitted by: Peter Dolding (oiaohm)

https://help.libreoffice.org/Common/Using_Remote_Files

CMIS has extra meta data like modification history of who has modified the files. Having a proxy that can talk CMIS to remote check out and check in files to CMIS solutions would useful. Its one thing to transfer files around its another thing to keep sane track of what files are current.