Fix invocation of Hunspell by ispell.el.

Fix invocation of Hunspell by ispell.el.

 lisp/textmodes/ispell.el (ispell-check-version): For hunspell, set
 ispell-encoding8-command to "-i", without a trailing space.
 (ispell-start-process): For hunspell, use '("-i" ENCODING), in 2
 separate command-line arguments, to specify the encoding, since
 that's how hunspell expects it.