Provides the base class and ParserElement base class to do initial parsing on the MsgObject.

ParserElement is a Java class that implements a few methods
Also contains a Hashtable to store name/value pairs (actually, it has a MsgObject and uses the enhanced hashtable found in there).
Key method is process() - it understands the grammar and how to parse it into name/value pairs and stores them in the Hashtable
Table:OAGCOMMON~Field:FLIGHTNO~Order:1 becomes:
Table = OAGCOMMON
Field = FLIGHTNO
Order = 1

Pre- and Post- process allow additional changes to be made for special cases
Process can be overwritten to do other special processing as well

The MraldParser uses the list of ParserElements is in parser.props file to determine which name/value pairs in the MsgObject to process.