This patch allows the user to load games using PGN files. The parsing
is not complete and has a bunch of work left to be done, but it's
okay for our use case here. It can load all of the games our PGN
exporter can save. As the Chess program impoves so can the PGN parser.
You can now copy the board state as Forsyth-Edwards Notation. You can
then paste this into other chess programs/games, or into ours when
it gets implemented.
This patch adds an option to the menubar for exporting the current
game as a PGN file. This file can then be read by other chess
programs (and ours eventually) to replay the game or analyze it.
The implementation is mostly PGN spec compliant, however the code
could use some more work. Particularly the `const_cast`s...
But it's a start. :^)
Fixup: Chess: Fixed hard-coded home path in unveil() call
Fixup: Chess: Removed castling flags from Move struct
The castling detection logic is done inside Move::to_algebraic()
now, removing the need for is_castle_short and is_castle_long flags
inside of the Move struct.
As much as I like the "test" piece set, I think "stelar7" is a much
better first impression for anyone opening the Chess game, so I
consider it a much more sensible default.
