Added tag v0.21 for changeset ae963ee79b49
Added support for 25k freq wordlist for dictionary as an HTML page.
Added tag v0.21 for changeset 1eb6aaa8caa6
Making release v0.21.
enchant was removed from Cygwin.
Mark word frequency based on Paul Nation BNC+COCA 25k wordfamily list.
Added new atricles.
Added word forms compiled by Paul Nation. Data was taken from Laurence Anthony's AntWordProfiler home page.