'dml' value for log_statement

Hi all,

Attaching patch provides new value 'dml' for log_statement.
Currently, The server logs modification statements AND data definition
statements if log_statement is set 'mod'.
So we need to set the 'all' value for log_statement and remove
unnecessary information
if we would like to log only DML.

This patch allows the user to set in detail the setting.
The server logs statement only when INSERT. UPDATE, DELETE and TRUNCATE
statement are executed.
( same as 'mod' value which does not log the DDL)

Comments?

Regards,

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Sawada Masahiko