[MLton] mlnlffigen is awesome (was: bootstrap problem)

[Henry Cejtin]

I completely agree that the use of MLB path variables is definitely shady.
The whole notion of ~/.mlton/mlb-path-map being used, although very convenient
when just doing things for oneself, is really a pain when exporting things.
(This is because if you want to use it, you have to change your HOME and set
up a sill fake directory with a .mlton in it.)
I would like a mlton flag which says to NOT use ~/.mlton/mlb-path-map and to
(optionally) provide a file to use instead.  Then things which are exported
should always use that method.