Samba auth and cleanups

This is a series of commits that build on: https://github.com/xbmc/xbmc/pull/5740 and
* Bumps samba to a version that supports smb2/3 protocol.
* Uses sambas builtin authentication
* Upgrade api usage to the non legacy api
* Uses our own samba config file instead of user global one
any reason to disable sendfile?