Updated Hebrew translation
Split chess-game.vala into multiple files

This is easily justified by observing that the majority of
chess-game.vala was devoted to the ChessState class.
warning: extra tokens at end of #endif directive
Split several files off into an internal library

This will be a static convenience library, so we don't have to recompile
all of these files for each test binary.
Remove the Claim Draw menu item

Instead, we should prompt the player when he has the option of claiming
a draw. This will come in the next commit.

https://bugzilla.gnome.org/show_bug.cgi?id=727345
Remove the gear menu

https://bugzilla.gnome.org/show_bug.cgi?id=727345
Switch to a Save As button

The standard Save is still available with Ctrl+S

https://bugzilla.gnome.org/show_bug.cgi?id=727345
Add a resign button

https://bugzilla.gnome.org/show_bug.cgi?id=727345
Restore chess-scene.c to POTFILES.skip

It doesn't actually have any translatable strings, so it's not strictly
necessary, but it should definitely be here as long as chess-scene.vala
is listed in POTFILES.in
Add ChessGame.can_claim_draw()

https://bugzilla.gnome.org/show_bug.cgi?id=727789
Prompt the player when claiming a draw is possible

https://bugzilla.gnome.org/show_bug.cgi?id=727789
trivial: move methods related to claim draw
Set reasonable defaults for global booleans

We actually need to set a default for allow_claim_draw_dialog to account
for cases where games are loaded instead of started new.

game_needs_saving should already be covered everywhere, but it doesn't
hurt to set this. By default, games don't need saved, since nothing has
happened yet.
Updated Hebrew translation