Centralise key objects through refactoring.

Refactored code across the board to employ VI_Profiles, VI_Settings and VI instantiated within the static GAVPI class - essentially centralising configuration.  While not entirely embracing design patterns (implementing a singleton would have required significant re-working and isn't entirely necessary since we're not multithreading) this will make it simpler to support multiple simultaneous Profiles at some later time, and provide a foundation for implementing a system tray icon fuctionality in future.