Stubs for crude fluent expression builder
Moved fluent api stubs into Language project
Refactor of expressions and replaced some ExpressionQueryParserTests with expression tree comparison
More changes to ExpressionQueryParserTests
Beginning of AggregatingExpressionFactory
Implemented more aggregator-based expressions. Fixed ParseAggregate method and renamed it to ParseSingleItemMember
Language improvements: MAX([*].Speed) is now MAX(Speed), [0].Speed is now 0.Speed