Fix path to the handbook and provide a hint about how to install it if it was not added at installation time.
Fix path to the handbook and provide a hint about how to install it if it
was not added at installation time.

Approved by:	re (blackend)

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