Help: Document add_custom_command PRE_BUILD/PRE_LINK for exe/lib only (#15059)

State explicitly that the PRE_LINK mode is not for targets created by
the add_custom_target command.  The existing wording for PRE_BUILD being
treated as PRE_LINK by non-VS generators will now imply this restriction
for PRE_BUILD too.
Fix used value warning.

packageFileName no longer has only one value in this function.  Move the
declaration into the loop and remove its initial and unused asignment.
Help: Add notes for topic 'vs-windows-phone-and-store'
Merge topic 'vs-default-ignore-libs'

c1580a92 VS: Always add IgnoreSpecificDefaultLibraries to .vcxproj files
29410df2 cmIDEOptions: Add an AppendFlag method to update multi-valued options
ExternalData: Drop 'not security software' disclaimer (#15060)

Let clients do their own research on the current strength of each
hash algorithm to choose what is best for their needs.

Suggested-by: Nico Schlömer <nico.schloemer@gmail.com>
Merge branch 'release'
CMake Nightly Date Stamp
Genex: Remove unnecessary check of context->Makefile

The context->Makefile is never NULL, but our checks for it convince
Clang scan-build that it might be NULL.  Then it warns about later
unchecked uses.  Drop the unnecessary checks.
file: Refactor internal implementation of file(STRINGS)

Make room for encoding support.
file: Add ENCODING option to file(STRINGS) command (#10519)

Support extraction of UTF-8 strings.
Merge topic 'file-strings-encoding'

5b30ec28 file: Add ENCODING option to file(STRINGS) command (#10519)
ffa373e7 file: Refactor internal implementation of file(STRINGS)
Merge topic 'CheckIncludeFiles-main-prototype'

bf89f910 CheckIncludeFiles: Use modern C declaration for 'main' (#15058)
Merge topic 'doc-add_custom_command'

5bf1c5cc Help: Document add_custom_command PRE_BUILD/PRE_LINK for exe/lib only (#15059)
2a58c872 Help: Revise and format 'add_custom_command' docs
cb88742d Help: Remove stray content from 'add_custom_command' docs
Merge topic 'fix_value_not_used'

2cac483e Fix used value warning.
Merge topic 'ExternalData-drop-security-disclaimer'

f2ccc14b ExternalData: Drop 'not security software' disclaimer (#15060)
Genex: Do not consider 'head' when evaluating build properties

When $<TARGET_PROPERTY> names a build property like COMPILE_DEFINITIONS
but not the usage requirement (INTERFACE_) version of it, the value
should be that used to build the target.  It should not be influenced by
a dependent 'head' target like usage requirements are.

Extend the CompileDefinitions test with a case covering the corrected
behavior.

Reviewed-by: Stephen Kelly <steveire@gmail.com>
Doxygen: Add CPack/IFW subdir to doxyfile.in INPUT section
Doxygen: Add STRIP_FROM_PATH variable to doxyfile.in

This helps to better perceive information
CMake Nightly Date Stamp
create_test_sourcelist: Suppress MSVC warnings in test driver (#15066)

Suggested-by: Ken Moreland <kmorel@sandia.gov>