scmutil: introduce binnode(ctx) as paired function with intrev(ctx) It seemed silly to convert ctx.hex() back to binary to use node.hex/short(), or to use [:12] instead of node.short() because ctx.node() could be None. Eventually I want to change wctx.rev() and wctx.node() to return wdirrev and wdirid respectively, but that's quite big API breakage and can't be achieved without some compatibility wrappers.