Refactor array/hashtable processing

[plastikfan]

Having discovered this article: Hashtable and Array tips

a review needs to be made on the entire codebase to make sure no bad practices are being employed.

[plastikfan]

The following improvements will be made:

• Replace all ArrayList with System.Collections.Generic.List as per Microsoft recommendations
• All array construction should be done via a pipeline instead of manual iteration and the use of the Add method (where possible and appropriate)
• avoid using += for array construction; it's inefficient for large collections