Paranoia: instead of a NULL conversation function, use one that always returns PAM_CONV_ERR; moreover, make sure we always have the right conversation function installed before calling PAM service functions. Also unwrap some not-so-long lines.
Paranoia: instead of a NULL conversation function, use one that always
returns PAM_CONV_ERR; moreover, make sure we always have the right
conversation function installed before calling PAM service functions.
Also unwrap some not-so-long lines.

MFC after:	3 days

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