GHCi 5.00.1: packages can now be loaded at the prompt

[Simon Marlow]

A new feature slipped into 5.00.1, but it looks like the documentation
to go with it didn't get merged (probably my fault, sorry about that).
You can now load packages from the GHCi prompt, like so:
   ___         ___ _
  / _ \ /\  /\/ __(_)
 / /_\// /_/ / /  | |      GHC Interactive, version 5.00.1, For Haskell
98.
/ /_\\/ __  / /___| |      http://www.haskell.org/ghc/
\____/\/ /_/\____/|_|      Type :? for help.

Loading package std ... linking ... :done.
Prelude> :set -package lang
Loading package lang ... linking ... done.
Prelude> :set -package util
Loading package concurrent ... linking ... done.
Loading package posix ... linking ... done.
Loading package util ... linking ... done.
Prelude>=20

This means you can also load packages from .ghci files too.

Cheers,
	Simon