The Read and Verify a String routine reads a sequence of
    characters and verifies the sequence.

    Format

      SMG$READ_VERIFY  keyboard-id ,resultant-string ,initial-string

                       ,picture-string ,fill-character

                       ,clear-character [,prompt-string]

                       [,modifiers] [,timeout] [,placeholder-arg]

                       [,initial-offset] [,word-terminator-code]

                       [,display-id] [,alternate-echo-string]

                       [,alternate-display-id] [,rendition-set]

                       [,rendition-complement] [,input-length]