* lisp/ob-haskell.el (org-babel-haskell-initiate-session): Implement
sessions.
(org-babel-haskell-with-session): New macro to manage sessions.
(org-babel-interpret-haskell): Refactor code. Use
`org-babel-haskell-with-session` to manage sessions.
* testing/lisp/test-ob-haskell-ghci.el: Update tests related to
sessions.
* lisp/ob-haskell.el (org-babel-interpret-haskell): When the result
type is 'value, use the last value as defined by GHCi.
(org-babel-haskell-eoe): New default value.
(org-babel-interpret-haskell): Update for the new value of `org-babel-haskell-eoe'.
* testing/lisp/test-ob-haskell-ghci.el: Update tests related to output/value.
Ihor Radchenko
Kyle Meyer
Bruno BARBIER