A bunch of changes (been waiting for the link to cvs.haskell.org to
come back):

- Two new flags -ignore-dot-ghci and -read-dot-ghci control the
  reading (or not) of ./.ghci and $HOME/.ghci.  This will be useful
  for automatic testing of GHCi.

- A new option -package-conf <file> allows reading an additional
  package.conf file, which can be used to keep a per-user set of
  packages.

- GHCi now fails gracefully on startup if linking the libraries
  specified on the command-line fails.