Extend queries to support CalculatedLiterals

CalculatedLiterals are literal values are calculated on the entire
data set and then the calculated value is used as a Literal.

Add three new operators:

`grand`: A grand total literal.
`pcttotal`: Return the pct of total for each value. 
`sharechange`: Return the difference in pcttotal between two expressions
Return queries in a consistent order.
Add pct total and share change operators