* [bzip2] add a "tool" feature to control the build of bzip2.exe
This is modelled after curl[tool], but it is on by default for
compatibility with the existing portfile.
* x-add-version, format
* Fix bzip2 git-tree.
* Remove deprecated rules
* update bzip2 git-tree
* Add the bzip2-1.0.6 SPDX license identifier
* treeish
Co-authored-by: Billy O'Neal <bion@microsoft.com>