improve reliability of Inflector.transliterate

Hello,

I'd like to ask for some feedback on a patch I just submitted.

The patch improves the reliability of
ActiveSupport::Inflector.transliterate, which currently does not
handle many characters from Danish, Swedish, Icelandic, Polish and
other European languages.

This is because the current code relies upon UTF-8 decomposition, but
many common characters do not in fact decompose to an ASCII letter and
a diacritic. Two very common examples are Scandanavian "ø" and German
"ß".

If you don't speak any of the affected languages, imagine if the
current method deleted all ocurrences of the letter "s" from English
strings, and so generated paramater strings like:
"234-aint-loui-cardinal" rather than "234-saint-louis-cardinals".

In a nutshell, the difference to developers is:

Inflector.parameterize("Ærøskøbing")
# before patch: "rskbing"
# after patch: "aeroskobing"

Patch: http://gist.github.com/363923
LH ticket: https://rails.lighthouseapp.com/projects/8994-ruby-on-rails/tickets/4374-inflectortransliterate-fails-on-many-european-characters#ticket-4374-2

Regards,

Norman