8835d5d2f1 make bip21 schema lowercase (Riccardo Casatta)
Pull request description:
The spec RFC3986 specifies the scheme is case insensitive and we were uppercasing to optimize QR code representation.
Unfortunately, common platform such as Android seems to fail to recognize uppercase schema, so for compatibility reason we use lowercase.
close#1843
ACKs for top commit:
Kixunil:
ACK 8835d5d2f1
apoelstra:
ACK 8835d5d2f1
Tree-SHA512: 02d228b52fe4df20edb71ba8e2ab8a2bae4b912252e30a3150ee3af74e65a6e91b165c9579273b57e894366c9792a8312ea973723cd8c5d98037aaba80d7cf07