Change License

This changes the effective license from a simple Apache-2.0 license to a
dual license consisting of both Apache-2.0 and the MIT license to be more
compatible for use in GPL Code.

The MIT license requires reproducing countless copies of the same copyright
header with diffferent names in the copyright field, for every MIT library
in use.  The Apache license does not have this drawback.  However, this is not
the primary motivation for creating these issues.  The Apache license also has
protections from patent trolls and explicit contribuition licensing clause.
However the Apache license is incompatible with GPLv2.  This is why Rust is
dual-licensed as MIT/Apache (the "primary" license being Apache, MIT only for
GPLv2 compat), and doing so would be wise for this project.  This also makes
this crate suitable for inclusion and unrestricted sharing in the Rust
standard distribution and other projects using dual MIT/Apache.

src/main.rs

@@ -1,17 +1,10 @@
 /*
- *    Copyright 2023 Anthony Oteri
+ * Copyright 2023 Anthony Oteri
  *
- *    Licensed under the Apache License, Version 2.0 (the "License");
- *    you may not use this file except in compliance with the License.
- *    You may obtain a copy of the License at
- *
- *        http://www.apache.org/licenses/LICENSE-2.0
- *
- *    Unless required by applicable law or agreed to in writing, software
- *    distributed under the License is distributed on an "AS IS" BASIS,
- *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- *    See the License for the specific language governing permissions and
- *    limitations under the License.
+ * Licensed under the Apache License, Version 2.0, <LICENSE-APACHE or
+ * http://apache.org/licenses/LICENSE-2.0> or the MIT license <LICENSE-MIT or
+ * http://opensource.org/licenses/MIT>, at your option. This file may not be
+ * copied, modified, or distributed except according to those terms.
  */
 
 #![deny(clippy::pedantic)]