Add round() function for ExecuteSQL

Idea created by monkeybreadsoftware on Sep 30, 2017

    A few math functions are missing as far as I noticed.


    Recently we missed round() function.


    ExecuteSQL ( "SELECT round(Points) FROM Jobs" ; "" ; "")


    where round would just do like in SQLite:

    The round(X,Y) function returns a floating-point value X rounded to Y digits to the right of the decimal point. If the Y argument is omitted, it is assumed to be 0.