Fixed psql double quoting of SQL ids

doc/src/sgml/libpq.sgml

doc/src/sgml/ref/psql-ref.sgml

src/bin/psql/command.c

src/bin/psql/common.c

src/bin/psql/create_help.pl

src/bin/psql/describe.c

src/bin/psql/help.c

src/bin/psql/input.c

src/bin/psql/input.h

src/bin/psql/large_obj.c

src/bin/psql/mainloop.c

src/bin/psql/print.c

src/bin/psql/prompt.c

src/bin/psql/prompt.h

src/bin/psql/startup.c

src/bin/psql/stringutils.c

src/bin/psql/stringutils.h

src/bin/psql/tab-complete.c

src/interfaces/libpq/fe-auth.c

src/interfaces/libpq/fe-connect.c