Readline read_history and write_history addition

[Alexander Dunlap]

Hello all,

I'd like to propose the addition of read_history and write_history
bindings to the readline library. I believe I've followed the
instructions on the Haskell wiki appropriately and I've set up a
ticket (with a patch) at
http://hackage.haskell.org/trac/ghc/ticket/2053.

Essentially, the patch adds simple bindings so that Haskell programs
can use Readline's read_history and write_history functions. This will
be useful for the implementation of
http://hackage.haskell.org/trac/ghc/ticket/2050 (add persistent
history to GHCi) and potentially other applications.

Thanks for your time and consideration.

Alex