Added NFKD normalization
Unit test for utf-8 NFKD
Removed full spec, added link to BIP39 paper
version 0.7
add one missing check to unit utf-8 test
Check if mnemonic and passphrase are string values
Fix typo
Added helper normalize_string() for performing UTF8 NKFD normalization
Version 0.8
Fixed handling of utf8 in normalize_string
Merge branch 'master' of github.com:trezor/mnemonic