Ox: Attribute Grammar Compiling System oxml2m4

- update Autoconf generated file due to change [r 141]

- special case handling for macOS Homebrew GNU C/C++ compiler versions 12-14: add flag '-mmacosx-version-min=<macOS major version>.0' to 'AM_CXXFLAGS'
- [regression testing]: the macOS Command Line Tools for Xcode 26.3 clang 'integrated assembler' warns about overriding deployment version from '16.0' to '26.0' invoked from these compilers
- special case handling for macOS Homebrew LLVM C/C++ compiler versions 16-20: add flag '-mmacosx-version-min=<macOS major version>.0' to 'AM_CXXFLAGS'
- [regression testing]: avoid warnings from the macOS Command Line Tools for Xcode 26.3 clang when linking with libraries built for macOS version 26.0

- update to Automake 1.18.1 versions

- add updated README, ChangeLog, and NEWS

- update significant changes in the OXML translator 1.4 release

- update change summary log

- fixed a typo

- add updates to installation and to instantiate the settings for the "XML Language Support by Red Hat" Microsoft Visual Studio Code (vscode) extension

- add README updates

- add the settings and settings template for the Microsoft Visual Studio Code (vscode) "XML Language Support by Red Hat" extension