reorganize files
Major code reorganization
Flatten the N/Rev class relationship

Instead of having a linked list of N's that all contain a .data
attribute of a Rev, let's just have Revs be the linked nodes
directly.
renamed oldest to newest as that's what it's doing
unneeded declaration
Move history building elsewhere, rearragne bisection and generate HTML and XML output

Note that it was an incredibly poor choice to implement HTML generation with ElementTree!