add postgres's regex operator for more powerful searching?

This small patch adds the very powerful postgres regex operator to OpenObject searches:
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openerp-server/osv/expression.py
-OPS = ('=', '!=', '<>', '<=', '<', '>', '>=', '=?', '=like', '=ilike', 'like', 'not like', 'ilike', 'not ilike', 'in', 'not in', 'child_of')
+OPS = ('=', '!=', '<>', '<=', '<', '>', '>=', '=?', '=like', '=ilike', 'like', 'not like', 'ilike', 'not ilike', 'in', 'not in', 'child_of', '~', '~*')
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Adding the '~' and '~'" operators will give OpenERP access to Postgres's excellent regular expression engine for searches; much more power than 'like'. This tiny patch works for great for me, would love to see it in the trunk.
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Optionally?...Perhaps 'not ~' and 'not ~*' should be added also?
But that may require many more lines are touched; especially all the occurrences of

                            if operator in ['not like','not ilike','not in','<>','!=']:

which by the way, would be more maintainable as one preamble copy of

not_operators=['not like','not ilike','not in','<>','!=','not ~','not ~*']

used by all the lines like this

                            if operator in not_operators: