Make GHC accept Unicode source files

GHC currently only accepts source files in the Latin-1 character set, which is a small (8-bit) subset of the full Unicode character set.

GHC should be able to accept fulll Unicode source files, encoded appropriately (eg. UTF-8).

See this message for some more information on the problem:

http://haskell.org/pipermail/glasgow-haskell-users/2003-December/006094.html