This is the "Arc Consistency Crossword Compiler", or arccc.

To run the program:

arccc <grid> <dictionary>

The grid file is a block of . # or letters.  For example, a 3x3 grid
with the top-right and bottom-left squares filled, and an 'a' in the
center blank is given by:

..#
.a.
#..


The grid parser is currently not very robust.  Do not add any blank
lines nor spaces to the file.

The dictionary is just a list of words.  Currently, if a word starts
with an uppercase letter, it is not used in filling the grid.

Currently, the program prints out a working fill when it encounters
one, but continues generating fills until killed or exhausting all
possibilities.