Revert "Use haskell-process-live-p (refs #165)."

After investing some time experimenting with with
Emacs 23.4.1 (which lacks process-live-p) I'm reverting
this commit as it has no effect whatsoever as the real fix
for #165 has already been provided via 7fe02abb.

This reverts commit 1adc6988d571851d2cbf2359227eb0ae4e71dfe6.