r5518: Add initial msdfs support to smbclient. Currently I can only

r5518: Add initial msdfs support to smbclient.  Currently I can only
cd up and down the tree and get directory listings.

Still have to figure out how to get a directory listing on a
2k dfs root.  Also have to work out some issues with relative paths
that cross dfs mount points.

We're protected from the new code paths when connecting to
a non-dfs root share ( the flag from the tcon&X is stored
in the struct cli_state* )
(This used to be commit e57fd2c5f00de2b11a2b44374830e89a90bc0022)