The global help key CTRL-g has changed to F1.

The global help key CTRL-g has changed to F1.

More code reorganization. Each game mode has it's own function that
takes the key pressed as an argument. Now different game modes can
have the same key as other modes like before, but alot easier to
maintain.

.tag in GAME is now an array of TAG pointers. pgn_add_tag(),
pgn_tag_free() and pgn_sort_tag() have changed.

Added function pgn_tag_total(TAG **) to return the number of tags.

Cleanups for game pointers. (*g). is now g->.

BOARD is back in GAME again. Figured that later on when multiple games
are being played the global 'board' will be updated by other games and
cause confusion. Switching between two games with one in edit mode and
another in play mode demonstrates this. Also pgn_new_game() no longer
takes a BOARD parameter.

history_next() and history_previous() no longer take the
'whole/halfstep' argument.

New colors for the window titles and prompt that are more readable for
me.