Sudoku MC

Console based sudoku solver. It is a modified version
of the solver included in the Ubuntu distribution of Linux,
and has similar functionality to the original by Michael Kennett.

New features:
- You interactively can open and save boards with it.
- The title of the board can be edited.
- Added early contradiction check to detect if the board is unsolvable:
1 2  . | .   .  . | . . .
.   .  . | 1 2  . | . . .
.   .  . | .   .  . | 1 2 .
-------+-------+-------
2 1  . | .   .  . | . . .
.   .  . | 2 1  . | . . .
.   .  . | .   .  . | 2 1 .
-------+-------+-------
.   .  . | .   .  . | . . .
.   . 2 | .   . 1 | . . .
.   . 1 | .   . 2 | . . .

- Contains a default template, so it can run on it's own, without any additional external file.
- The embedded template can be saved to disk. It will be used if specified as an input argument, or just exists in the working directory, so you still can customize.