plproxy - plproxy: Make scanner accept dot as standalone symbol

Log Message:
-----------
Make scanner accept dot as standalone symbol

Currently PL/Proxy fails to parse following query:

  select (ret_numtuple(1)).num, (ret_numtuple(1)).name;

The fix is to add "." to the SQLSYM rule in the lexer.  This should be OK
because an identifier chain will always be longer than a single dot, so flex
will prefer it over parsing the single dot.

Patch by Peter Eisentraut

Modified Files:
--------------
    plproxy/expected:
        plproxy_select.out (r1.3 -> r1.4)
        (http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/plproxy/plproxy/expected/plproxy_select.out?r1=1.3&r2=1.4)
    plproxy/sql:
        plproxy_select.sql (r1.2 -> r1.3)
        (http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/plproxy/plproxy/sql/plproxy_select.sql?r1=1.2&r2=1.3)
    plproxy/src:
        scanner.l (r1.14 -> r1.15)
        (http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/plproxy/plproxy/src/scanner.l?r1=1.14&r2=1.15)