mysqlcompat - mysqlcompat: Add <=> null safe comparison.

Log Message:
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Add <=> null safe comparison.  Move all files to root dir.

Added Files:
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    mysqlcompat:
        comparison.sql (r1.1)

(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/mysqlcompat/mysqlcompat/comparison.sql?rev=1.1&content-type=text/x-cvsweb-markup)
        controlflow.sql (r1.1)

(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/mysqlcompat/mysqlcompat/controlflow.sql?rev=1.1&content-type=text/x-cvsweb-markup)
        mathematical.sql (r1.1)

(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/mysqlcompat/mysqlcompat/mathematical.sql?rev=1.1&content-type=text/x-cvsweb-markup)
        string.sql (r1.1)

(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/mysqlcompat/mysqlcompat/string.sql?rev=1.1&content-type=text/x-cvsweb-markup)

Removed Files:
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    mysqlcompat:
        mysqlcompat.sql
        (http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/mysqlcompat/mysqlcompat/mysqlcompat.sql)
    mysqlcompat/8.x:
        controlflow.sql
        (http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/mysqlcompat/mysqlcompat/8.x/controlflow.sql)
        mathematical.sql
        (http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/mysqlcompat/mysqlcompat/8.x/mathematical.sql)