HFST library, tools and utilities' thanks file

The initial work on HFST was conducted by HFST Research Team found in AUTHORS
file.

Many people further contributed by reporting problems, suggesting various
improvements or submitting actual code. Here is a list of these people. Help me
keep it complete and exempt of errors.

Antti Karttunen
Børre Gaup
Daniel Ridings
Francis Tyers
Harri Pitkänen
Janne Peltonen
Jyrki Niemi
Laura Salo
Sjur Moshagen
Trond Trosterud

and all students in university of Helsinki courses, who we’ve forced to beta
test this software :-)
