p - partialy done, c - done, but not checked =), d - done, but leaved
here for some reason

very high priority:
[ ] all read()s/write()s doesnt check return value =/
    but i'm too lazy to fix it =)

primary:
[ ] looks like we have memory leaks =/
[d] After turning on "show next balls" next balls isnt shown till
    redraw occurs. gtk+ bug? probably. (added workaround)

secondary:
[ ] option to remove not only "lines", but just some "connected"
    "balls". i.e:

    ggg
      g
     gg

    and, maybe, squares/triangles/etc.
[ ] make "internal" theme
[ ] recursive calls of new_game()/new_turn(). should i change it?
[ ] fix "casuses" in preferences ("next" already checked in reinit_board())

never?:
[d] remove *sleep*'s (now, when i think of it, i think it is unneeded)
    (replaced with gettimeofday() + gtk_iteration_do())
[ ] "unlimited" undo (tell me the reason to do that =/)
[ ] sound (_what_ sound must be in such game? blam blam
           when ball jumps? it will annoy player, imho.
           music? why dont turn on some cd? so, if
           someone can tell me what fsckin sounds should
           be here i will think about adding it...)