corrected 2 typos in README
fixed typo in utf8-hack.lisp
Added a function $set_alpha_char that does the work of set-alpha-char but can also be used from the lisp top level to add wide characters manually.
This necessitated a change in the data structure stored in utf8-hack-data.lisp, which is now a list of conses of the form
("DESCRIPTION OF CHARACTER" . CHARACTER).