* Got ISNULL working
* Allow function calls with no arguments
* Added no-else cases and arrays
* Added more operations including ilike, concat
* Added optional all to set operations and fixed natural join
* Ran astyle
* Used the appropriate star expression
Instead of using a ColumnRef with star literal.
* NULL expressions now returns true isLiteral
* Fixed structure for no-else case clauses
* Fixed up grammar conflicts