Replace 'ido-completing-read' with 'completing-read-function'
Declare 'delete-active-region' in haskell-indentation

Fixes the build error with emacs23 because delete-active-region is new in emacs24
Defvar completing-read-function
Replace completing-read-function with custom for haskell-mode

This should be backwards compatible with emacs23, which does not have
completing-read-function