I confess that I'm not entirely clear on what I'm trying to accomplish
with makedo.  It's just an exploration.

I just have the vague idea that writing scripts like
handwritten.do.bash is
horrible, that part of the horribleness is due to dimensionality
(eg. we want to explore
       N sentence selection methods
     * N llr computation methods
     * N data selection methods
)

Another part of the horribleness is that cached computations can
only be pointed to by filenames, so a lot of what I'm doing in my
scripts is essentially parsing filenames with basename and dirname
or assembling them.

Scratch pad
-----------
Ideas I seem to be exploring so far:

- dependencies : foo needs bar, make sure bar is is built

- variants  : there is more than one way to do bar

- iteration : for all files in dir with ext X do foo(X)
              targets not known beforehand, must do ls first