`CMAKE_CURRENT_FUNCTION`
Can be used for diagnostic or debugging messages like the
`__PRETTY_FUNCTION__` macro of GCC.
`CMAKE_CURRENT_FUNCTION_LIST_DIR`
Eliminates the necessity of the additional "global"
variables inside a module used to access additional "resource"
files from functions defined in the module.
...
Revise docs for all "Scripting Commands", except four find_XXX
that use a macro suite of their own.
* Take full advantage of the improved syntax highlighting.
* Make consequential use of <..> placeholders.
* Clarify things here and there in the text.
Specific improvements to some command docs:
* "math": Correct description of novel hexadecimal capability.
* "if", "foreach", "while": Provide link to "endif" etc
* "foreach", "while": Mention "break" and "continue".
* "foreach": Simplify explanation of ``RANGE`` and ``IN`` signatures;
advise against negative arguments or reverse ranges (compare issue #18461)
* "endif", "endfunction" etc: Explain that the argument is optional and
maintained for compatibility only
Add notes about macro arguments in the foreach, if, and list commands.
Add a section to the macro command documentation explaining in detail
how macro arguments are not variables.
