Now with BSP Trees

Here's the most recent list of changes to Vega Strike... VS is pretty dashed confusing, but fun to play with. Much like Ultima VIII.

• BSP trees now work perfectly for both line and starship collisions.
• this means that, unlike vegastrike classic, you'll be able to fly close to the hull of a large starship, hug the deck, fly through the launch bay...
• Any closed model (eg Midway) can only be hit by a well placed beam (no hitting if you fire between the legs of those Midway pants)
• This also will make way for skin-tight shield effects on those large ships!
• an optimized BSP tree generator is available that can generate trees for Vegastrike and even for prophecy.
• this generator can minimize the size of the tree or the time it takes to search through it, using ideas inspired from the crystal space engine (http://crystal.sourceforge.net)
• if anyone has any ideas how to enforce the closed-ness of a model, please let me know. Currently many of the vegastrike classic models are "open" and have gaps in them that allow you to collide, mid-space! (bad things)
• These BSP trees are the last _major_ challenge to getting vegastrike working.
• from here on out it's all details associated with gameplay and organization, as opposed to new algorithms I need to learn.