[m-rev.] for (possibly post-commit) review: simplify the creation of .int files

[Zoltan Somogyi]

This is the major part of step 1d of the plan. I would like to start
working on the minor part, simplifying the code that creates .int2
files from .int files, so this diff keeps the old, convoluted code for
creating .int files, and checks that the new code generates the exact
same output.

Given that fact, and given that this diff has passed a hlc bootcheck cleanly,
are people ok with me committing this diff now? And does anyone
want to put their hand up to say they will review it?

Zoltan.