Provide support of diverse BTC addresses

[bnvk]

The following are the types of Bitcoin addresses I am aware of are:

• Bech32 - native Segwit - BIP173
• P2SH - backwards compatible Segwit / multi signature - BIP16
• Singlesig - single signature
• WIF - wallet import format

There was a commented stub function in ProTip as previously Bitcoinjs did not support mixed normal and multisig inputs, but a patche has been merged in now. The point of this issue is:

• Offer subtle UI hints (info bubbles?) to the user where applicable
• Properly parse addresses on sites as the right type
• Implement testing coverage
• Implementing full Segwit support Upgrade wallet to be SegWit compatible #18