math functions in queries

[gavinking]

The following functions are, I believe, supported on all major databases, and it seems to me that there would be value in adding them to the query language: power(), floor(), ceiling(), round(), sign(), ln(), exp(), sin(), cos(), tan(), asin(), acos(), atan(), atan2().

One might object that we don't typically need to do trigonometry in a typical query, and that's true, but since the databases themselves support these, along with both JDBC and ODBC in their function escape syntax, there's almost no cost to including these functions in the list.

If nobody objects to this idea, I will write up a proposal.