Previously, we were including the whole of <getopt.h> in <unistd.h>.
However according to the posix <unistd.h> doesn't have to contain
everything we had in <getopt.h>.
This fixes some symbol collisions that broke the git port.
We were getting a little overly memey in some places, so let's scale
things back to business-casual.
Informal language is fine in comments, commits and debug logs,
but let's keep the runtime nice and presentable. :^)
We were already borrowing a getopt() from the BSD family until the day
we write our own. This patch borrows a slightly more modern one so we
also get getopt_long().
Fixes#190.
See also #91 for the desire to eventually NIH our own getopt()..
