use new xpub/xprv prefixes for Segwit BIP49

[prusnak]

Please use the following constants for BIP49 xpub/xprv prefixes as per http://docs.electrum.org/en/latest/seedphrase.html#list-of-reserved-numbers

Bitcoin:

0x049d7878 yprv
0x049d7cb2 ypub

Bitcoin Testnet:

0x044a5262 upub
0x044a4e28 uprv

This will assure that user does not accidentally imports BIP49 xpub to BIP44 watch only wallet.

[mrjoshuap]

Would this allow me to watch a SegWit account?

I have a Trezor, and while I can watch a specific SegWit address, I am unable to see a SegWit account.

[prusnak]

Would this allow me to watch a SegWit account?

Exactly.

I am unable to see a SegWit account.

You need to use beta-wallet.trezor.io which shows Segwit YPUBs. This issue is precisely about adding support for these YPUBS.

[mrjoshuap]

I will gladly provide a +1 for this feature/issue!

[nathanfjohnson]

+1 for sure!

[johnwc]

If this is to allow importing ypub watch-only addresses, then +1 from me as well. I am currently unable to import a ypub watch-only address from Trezor wallet QR code.