dbi-link - dbi-link: Changed elog NOTICE and elog ERROR to warn and die,

Log Message:
-----------
Changed elog NOTICE and elog ERROR to warn and die, respectively.

Added comment on make_accessor_functions(), refresh_schema().

Added function reset_connection(data_source_id INTEGER).

Added SQL-callable wrapper functions for begin_work, commit and
rollback.

Modified Files:
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dbi-link:
dbi_link.sql (r1.8 -> r1.9)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/dbi-link/dbi-link/dbi_link.sql.diff?r1=1.8&r2=1.9)