Bitcoin Bech32

Encodes and decodes Bitcoin Segregated Witness addresses in the Bech32 format described in BIP-0173.

Example

```rust use bitcoinbech32::WitnessProgram; use bitcoinbech32::constants::Network;

let witness_program = WitnessProgram { version: 0, program: vec![ 0x00, 0x00, 0x00, 0xc4, 0xa5, 0xca, 0xd4, 0x62, 0x21, 0xb2, 0xa1, 0x87, 0x90, 0x5e, 0x52, 0x66, 0x36, 0x2b, 0x99, 0xd5, 0xe9, 0x1c, 0x6c, 0xe2, 0x4d, 0x16, 0x5d, 0xab, 0x93, 0xe8, 0x64, 0x33], network: Network::Testnet };

let address = witnessprogram.toaddress().unwrap(); asserteq!(address, "tb1qqqqqp399et2xygdj5xreqhjjvcmzhxw4aywxecjdzew6hylgvsesrxh6hy".tostring());

let decoded = WitnessProgram::fromaddress(address).unwrap(); asserteq!(decoded, witness_program); ```