basic fsh prototype (no comments yet)

*** 243,252 ****
--- 243,254 ----
          filio.h                 \
          flock.h                 \
          flock_impl.h            \
          fork.h                  \
          fsd.h                   \
+         fsh.h                   \
+         fsh_impl.h              \
          fss.h                   \
          fsspriocntl.h           \
          fsid.h                  \
          fssnap.h                \
          fssnap_if.h             \