Crashes etc.

[Hans Ronne]

The crashes in the new path code seem to involve garbage input from
blocked_by_enemy. It's unfortunate that this great addition got a bad
start, but hopefully the problems will be solved soon. Peter did test his
code for bugs extensively, but there were some last minute fixes of
problems that Eric and I found, and some of these changes involved the
blocking code.

Meanwhile, I have checked in some changes to the startup and module loading
code. This was prompted by problems with certain base module - submodule
configurations. The startup code now patches up the object references only
once, and is smarter about how it loads units into each other. I have
tested the new code thorougly, but it is of course possible that some
problem escaped me. Therefore, if you get init errors when you load a
module or saved game, please let me know.

Hans