renamed the package and the system name: aflab1 -> guicho-a-star (guicho-a* as a nickname)
big one commit

Conflicts:
	src/a-star-search.lisp
goal-p

additional key argument can be passed to `connect'

commit (stack-exhausted on sbcl 1.1.14)

Conflicts:
	src/mixin.lisp
commit

all rational

commit

unbound-slot automatically sets the value returned by generate-nodes

commit (stack-exhausted on sbcl 1.1.14)

Conflicts:
	src/a-star-search.lisp
bugfix