Pseudobot: Long Distance Calculations, Slam Fixes, and Lookup enhancements

All we need to do is calculate how
many yards away we are firing, find
the book that has the correct table,
remember the page number, etc. etc.

A potpourri of a buncha small things this week:

• Added a function that calculates long distance penalties. It defaults to miles, but supports other units as well.
• Fixed the DFRPG slam function, and made it its own. I got a little confused about the SM thing when reading it in the book, so now the damage should be correct.
• Enhanced the aggregation of page references in a lot of the lookup functions that use GCS data. This means that, if for example, a spell exists in GURPS Magic and in Dungeon Fantasy Spells, instead of showing just one page reference, it shows both. I bring up that example because it is among the most common, but it cropped up multiple times in multiple ways.