Enhance >export

[GregUtas]

Enhance the >export command with any of the following:

• The option to exclude statistics (e.g. the number of reads/writes/calls). Because export displays code in a canonical format with all comments stripped, it is useful for obtaining a diff of the entire code base. However, the statistics cause noise in such a diff.
• Options that allow generation of any subset of the (a) namespace view, (b) file view, and (c) class hierarchy.
• The ability to output a symbol that was #define'd as an empty string (e.g. #define NO_OP) when displaying code. Such a symbol is currently omitted. This is probably a complicated change because Lexer.Preprocess currently deletes any such symbol before parsing even occurs.