Bug fix to generate the correct dictionaries in make-hunspell-dict.

Before there were lines like:
  doit en_GB-ize "mk-list en_US $SIZE | src/deaccent"
which is clearly incorrect as it generating the wrong dictionary for
en_GB-ize.  Replace that with:
  doit en_GB-ize "mk-list en_GB-ize $SIZE | src/deaccent"
so the right dictionary is generated.

Oops. :(

Also make target directory (hunspell/) if it doesn't already exist.
Update README script to generate a Git version line instead of an SVN one.