Clarify some comments.
Clarify some comments.

struct rqelement, enum rqinfo_type, struct rqinfo, union rqinfou: add
lock requests.

Add declarations for freerq and unlockrange.  Since they include
request structures, they can't go in vinumext.h

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase