Use the Apache-2.0 license file without the appendix

This removes the appendix from the Apache-2.0 license file. The
license terms themselves are of course not modified. The license
terms end in "END OF TERMS AND CONDITIONS", which is retained, and
the appendix that follows it is removed.

This follows the practice in most or all of the repositories owned
by the Rust organization of using the Apache-2.0 license without
the appendix, on the grounds that it is confusing to keep it, as
the procedure described in the appendix for indicating that source
code is licensed Apache-2.0 is not actually followed in those
repositories: individual source code files are not being given
Apache-2.0 license headers. Note that this is merely an issue of
confusion; the appendix is not part of the terms of the license,
and no permission or limitation depends on whether it is included.

See rust-lang/rust#67734 for details.

Note that the license text itself must of course not be changed.
But this does not change it: the appendix, while it was part of the
license file, is expressly not part of the terms of the license.

Author: EliahKagan

Diff for: LICENSE-APACHE

@@ -175,28 +175,3 @@
       of your accepting any such warranty or additional liability.
 
    END OF TERMS AND CONDITIONS
-
-   APPENDIX: How to apply the Apache License to your work.
-
-      To apply the Apache License to your work, attach the following
-      boilerplate notice, with the fields enclosed by brackets "[]"
-      replaced with your own identifying information. (Don't include
-      the brackets!)  The text should be enclosed in the appropriate
-      comment syntax for the file format. We also recommend that a
-      file or class name and description of purpose be included on the
-      same "printed page" as the copyright notice for easier
-      identification within third-party archives.
-
-   Copyright [yyyy] [name of copyright owner]
-
-   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.