bsdconfig: Comments

My current style is to copy C for "/* NOTREACHED */" instead of spelling
out "Not reached". Make this one nominal change in this one file and the
others later.

While here, word-smith "Preload" into "Pre-load" as I believe that to
be more grammatically correct in this instance.

Also while here, fix a comment capitalization error.

Lastly, bump copyright for above changes.