pgsql: I have applied the following patch to document PQinitSSL() and

Log Message:
-----------
I have applied the following patch to document PQinitSSL() and
PQregisterThreadLock().

I also remove the crypt() mention in the libpq threading section and
added a single sentence in the client-auth manual page under crypt().
Crypt authentication is so old now that a separate paragraph about it
seemed unwise.

I also added a comment about our use of locking around pqGetpwuid().

Modified Files:
--------------
    pgsql/doc/src/sgml:
        client-auth.sgml (r1.83 -> r1.84)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/client-auth.sgml.diff?r1=1.83&r2=1.84)
        libpq.sgml (r1.196 -> r1.197)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/libpq.sgml.diff?r1=1.196&r2=1.197)
    pgsql/src/interfaces/libpq:
        fe-auth.c (r1.106 -> r1.107)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/interfaces/libpq/fe-auth.c.diff?r1=1.106&r2=1.107)
        fe-secure.c (r1.72 -> r1.73)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/interfaces/libpq/fe-secure.c.diff?r1=1.72&r2=1.73)