RB: Refactoring Matching Engine to prepare for implementing active/passive trading modes
RB: Add clean shutdown for messaging code; add Trading Mode enumeration.
RB: Modifying order matching engine to be a library that can be invoked from a Windows Service or a Console Application for testing.
RB: Add market order validation
RB: Create new Windows Service that starts the order matching engine via the order matching library
RB: Create Order Matching Console application for testing the Order Matching Library as a console application