BIP39: update status to Final, remove discourage comment summary

[scgbckbone]

• also widely deployed

[jonatack]

cc BIP author @prusnak

[katesalazar]

NAK to changes out of process

[prusnak]

Honestly, I could not care less what this repository says for this BIP. Reality is that literally all hardware wallets and vast majority of software wallets use BIP39.

The BIP process back in the days was a disaster. We were forced to add certain features to the BIP (which we did not like) to satisfy the reviewers, then they said they did not like the changes anyway and they will not recommend using it. All this negative feedback happened more than a half a year ago after we started to use BIP39 in Trezor, so we could not do any further changes.

I recommend all wallets to consider using SLIP39 which has better wordlist, better checksum and can generate shamir secret shares. The only drawback is that the backup is now 20 words instead of 12 (for 128 bit of entropy).

[scgbckbone]

I've reverted the comment back & rebased. Moving to final is "good enough" for now.

[katesalazar]

ACK 829afccd1ae26403f8c3583d7347b04aeb54c2ca