Use the same default arrows as readline

This should make it so people don't encounter things like #54 / technomancy/leiningen#997 Readline itself hard-codes in arrow key behavior (why? no idea.), and so sometimes default `inputrc` files will leave these keybindings out.

I think maybe the additional `[` was just a typo in the original commit, jline/jline2@f728bf8e (search "OH" on that commit; I wasn't able to find a way to link directly to the line), since the other settings are all properly carried over from readline. @gnodet can you confirm?

See http://git.savannah.gnu.org/cgit/readline.git/tree/readline.c?id=9922d2d7608ea86ff9e42aca0d3342a92748873f#n1128 for the readline implementation.

This works for my default Ubuntu install with no inputrc modifications.