pgsql: Somehow I missed some parser changes, so this commit comes pretty

[meskes(at)svr1(dot)postgresql(dot)org (Michael Meskes)]

Log Message:
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Somehow I missed some parser changes, so this commit comes pretty late. I just synced the parser of ecpg against the backend version, but still have to sync the lexer.

Also I fixed a bug in a bug fix I committed a few weeks ago. he check for a varchar pointer was incomplete.

Modified Files:
--------------
    pgsql/src/interfaces/ecpg:
        ChangeLog (r1.292 -> r1.293)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/interfaces/ecpg/ChangeLog.diff?r1=1.292&r2=1.293)
    pgsql/src/interfaces/ecpg/preproc:
        keywords.c (r1.68 -> r1.69)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/interfaces/ecpg/preproc/keywords.c.diff?r1=1.68&r2=1.69)
        preproc.y (r1.310 -> r1.311)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/interfaces/ecpg/preproc/preproc.y.diff?r1=1.310&r2=1.311)