Related to #18 

This sets correct ShareAccess values for rename and unlink requests.
See https://msdn.microsoft.com/en-us/library/cc246502.aspx ShareAccess.

ShareAcess was always set to 0x00. For rename and delete requests
it is required to include the 0x04 flag.

+ readdir() with stats:true option
+ added stat() command
+ cleared readFile() return type

Fixes #68

Should fix compatibility with Node 5.10.

Fixes #51

Fixes #49

Readdir only lists 510 items. This fix returns the full directory listing.

See https://github.com/Node-SMB/marsaud-smb2/blob/7979fa0c1b362936caf2646bb19c70c4e2d842a7/lib/smb2.js#L7