HS: investigations

It's been a while - Dev Diary has moved city and changed job. Here's a screenie of where investigations are currently at:

You can see a list of investigators down the LHS, and the main body is currently just a collection of simple buttons with time limits on them. Once one button is completed, one of the next buttons becomes available. After a little refactoring tonight, I'm now in a position to add 'rewards' to buttons so that completing certain phases of the investigation will add alien artifacts to the player's artifact list. I'll need to create a new Neoforce window for managing artifacts, leading inexorably towards some kind of tech tree.