Introduce SPDX identifiers

Recently we introduced SPDX identifiers into `rust-bitcoin`. In brief,
SPDX identifiers are a way to fully describe the license of a source
file in a single line. In addition to this we use an optional "written
by" line to give attribution to the files original developer if they
wish to have it.

- Add links to the SPDX website in the readme
- Add SPDX line to files with no license blurb
- Shorten the author section to a single line while maintaining the
  authors (add Sanket's email address to one attribution line)
- Remove all the licence information in each file and replace it with an
  SPDX ID (see https://spdx.dev/ids/#how)

Author: heap-coder

README.md

@@ -53,6 +53,14 @@ architectural mismatches. If you have any questions or ideas you want to discuss
 please join us in
 [##miniscript](https://web.libera.chat/?channels=##miniscript) on Libera.
 
-# Release Notes
+
+## Release Notes
 
 See [CHANGELOG.md](CHANGELOG.md).
+
+
+## Licensing
+
+The code in this project is licensed under the [Creative Commons CC0 1.0
+Universal license](LICENSE). We use the [SPDX license list](https://spdx.org/licenses/) and [SPDX
+IDs](https://spdx.dev/ids/).

src/descriptor/bare.rs

@@ -1,15 +1,5 @@
-// Miniscript
-// Written in 2020 by rust-miniscript developers
-//
-// To the extent possible under law, the author(s) have dedicated all
-// copyright and related and neighboring rights to this software to
-// the public domain worldwide. This software is distributed without
-// any warranty.
-//
-// You should have received a copy of the CC0 Public Domain Dedication
-// along with this software.
-// If not, see <http://creativecommons.org/publicdomain/zero/1.0/>.
-//
+// Written in 2020 by the rust-miniscript developers
+// SPDX-License-Identifier: CC0-1.0
 
 //! # Bare Output Descriptors
 //!

src/descriptor/checksum.rs

@@ -1,3 +1,5 @@
+// SPDX-License-Identifier: CC0-1.0
+
 //! Descriptor checksum
 //!
 //! This module contains a re-implementation of the function used by Bitcoin Core to calculate the

src/descriptor/key.rs

@@ -1,3 +1,5 @@
+// SPDX-License-Identifier: CC0-1.0
+
 use core::fmt;
 use core::str::FromStr;
 #[cfg(feature = "std")]

src/descriptor/mod.rs

@@ -1,16 +1,5 @@
-// Miniscript
-// Written in 2018 by
-//     Andrew Poelstra <apoelstra@wpsoftware.net>
-//
-// To the extent possible under law, the author(s) have dedicated all
-// copyright and related and neighboring rights to this software to
-// the public domain worldwide. This software is distributed without
-// any warranty.
-//
-// You should have received a copy of the CC0 Public Domain Dedication
-// along with this software.
-// If not, see <http://creativecommons.org/publicdomain/zero/1.0/>.
-//
+// Written in 2018 by Andrew Poelstra <apoelstra@wpsoftware.net>
+// SPDX-License-Identifier: CC0-1.0
 
 //! # Output Descriptors
 //!

src/descriptor/segwitv0.rs

@@ -1,15 +1,5 @@
-// Miniscript
-// Written in 2020 by rust-miniscript developers
-//
-// To the extent possible under law, the author(s) have dedicated all
-// copyright and related and neighboring rights to this software to
-// the public domain worldwide. This software is distributed without
-// any warranty.
-//
-// You should have received a copy of the CC0 Public Domain Dedication
-// along with this software.
-// If not, see <http://creativecommons.org/publicdomain/zero/1.0/>.
-//
+// Written in 2020 by the rust-miniscript developers
+// SPDX-License-Identifier: CC0-1.0
 
 //! # Segwit Output Descriptors
 //!

src/descriptor/sh.rs

@@ -1,15 +1,5 @@
-// Miniscript
-// Written in 2020 by rust-miniscript developers
-//
-// To the extent possible under law, the author(s) have dedicated all
-// copyright and related and neighboring rights to this software to
-// the public domain worldwide. This software is distributed without
-// any warranty.
-//
-// You should have received a copy of the CC0 Public Domain Dedication
-// along with this software.
-// If not, see <http://creativecommons.org/publicdomain/zero/1.0/>.
-//
+// Written in 2020 by the rust-miniscript developers
+// SPDX-License-Identifier: CC0-1.0
 
 //! # P2SH Descriptors
 //!

src/descriptor/sortedmulti.rs

@@ -1,15 +1,5 @@
-// Miniscript
-// Written in 2020 by rust-miniscript developers
-//
-// To the extent possible under law, the author(s) have dedicated all
-// copyright and related and neighboring rights to this software to
-// the public domain worldwide. This software is distributed without
-// any warranty.
-//
-// You should have received a copy of the CC0 Public Domain Dedication
-// along with this software.
-// If not, see <http://creativecommons.org/publicdomain/zero/1.0/>.
-//
+// Written in 2020 by the rust-miniscript developers
+// SPDX-License-Identifier: CC0-1.0
 
 //! # Sorted Multi
 //!

src/descriptor/tr.rs

@@ -1,4 +1,5 @@
-// Tapscript
+// SPDX-License-Identifier: CC0-1.0
+
 use core::cmp::{self, max};
 use core::str::FromStr;
 use core::{fmt, hash};

src/expression.rs

@@ -1,16 +1,5 @@
-// Miniscript
-// Written in 2019 by
-//     Andrew Poelstra <apoelstra@wpsoftware.net>
-//
-// To the extent possible under law, the author(s) have dedicated all
-// copyright and related and neighboring rights to this software to
-// the public domain worldwide. This software is distributed without
-// any warranty.
-//
-// You should have received a copy of the CC0 Public Domain Dedication
-// along with this software.
-// If not, see <http://creativecommons.org/publicdomain/zero/1.0/>.
-//
+// Written in 2019 by Andrew Poelstra <apoelstra@wpsoftware.net>
+// SPDX-License-Identifier: CC0-1.0
 
 //! # Function-like Expression Language
 //!