[ea] 16871: Even if the Session Manager is a degenerate subsystem, keep its include files in the include/subsys tree.

Even if the Session Manager is a degenerate subsystem, keep its include
files in the include/subsys tree.
Deleted: trunk/reactos/include/libs/sm/
Added: trunk/reactos/include/subsys/sm/
  _____

Copied: trunk/reactos/include/subsys/sm (from rev 16862,
trunk/reactos/include/libs/sm)