v0.20.0

[0.20.0]

APIs added

• Make backwards-compatible v2 to v1 sends possible.

APIs changed

• Removed contributeNonWitnessInput from v1 & v2.
• Allow receivers to make payjoins out of sweep transactions (#259).
• Encode &ohttp= and &exp= parameters in the &pj= URL as a fragment instead of as URI params (#298)