CPackWiX: Add variables for custom tool extensions and flags
Revert topic target_compile_features.
Merge topic 'target_compile_features' into next

e6a5ab9 Revert topic target_compile_features.
CMake Nightly Date Stamp
Help: Parse Copyright.txt instead of using current year

Configure our Sphinx conf.py with a copyright line extracted from
Copyright.txt instead of using the year in which the documentation is
built.  This will future-proof the reported copyright year range when
building documentation for old versions.
Merge topic 'cmake-copyright-year' into next

3bade75 Help: Parse Copyright.txt instead of using current year
Merge topic 'wix-custom-arguments' into next

096591b CPackWiX: Add variables for custom tool extensions and flags
Merge topic 'cleanup-edit_cache-target'

684063c Refactor tool selection for edit_cache (#14544)
eaf5b7a cmGlobalGenerator: Do not propagate const through GetCMakeInstance
Merge topic 'wix-custom-arguments'

096591b CPackWiX: Add variables for custom tool extensions and flags
Merge topic 'fix-INTERFACE-with-no-SHARED-libs'

64f73b0 add_library: Fix INTERFACE on platforms with no shared libs (#14561)
Merge topic 'create_test_sourcelist-clang-warnings'

ed675a9 create_test_sourcelist: Fix linkage in generated test driver code
Merge topic 'doc-ExternalData-network-path'

f3883f3 ExternalData: Show example network path URL template
ff6818b ExternalData: Format module documentation
Merge topic 'policy-summary-periods'

49cbca6 CMP0038: Add missing '.' to policy summary line
7390002 CMP0039: Add missing '.' to policy summary line
Merge topic 'cmake-copyright-year'

3bade75 Help: Parse Copyright.txt instead of using current year
2bbf6bd Copyright.txt: Add test to check year range
3ee67d0 Copyright.txt: Update year range to end in 2013
621ba1f cmake-gui: Parse Copyright.txt instead of duplicating notice
993b685 bootstrap: Parse Copyright.txt instead of duplicating notice
Merge branch 'master' into next
ExternalData: Allow local stores without any URL templates

Allow ExternalData_URL_TEMPLATES to be empty if a value for
ExternalData_OBJECT_STORES is provided.  Assume in this use case that
the object stores will already contain all needed objects.  Extend the
Module.ExternalData test to cover this case (all objects in stores).
Extend the RunCMake.ExternalData test to cover the non-failure message
case when stores are provided without URL templates.
Merge topic 'ExternalData-allow-no-urls' into next

8eb20ee ExternalData: Allow local stores without any URL templates
Drop use of configure_file IMMEDIATE option

Since commit 7d47c693 (Drop compatibility with CMake < 2.4, 2013-10-08)
we no longer need to use the configure_file IMMEDIATE option to support
compatibility modes less than 2.0.
set: Handle value-less PARENT_SCOPE explicitly

The code "set(VAR PARENT_SCOPE)" unsets VAR in the parent scope.
Implement this case explicitly next to where "set(VAR)" is explicitly
handled to unset VAR in the current scope.
set: Fix handling of empty value with PARENT_SCOPE

Just as

  set(VAR "")

sets VAR to an empty string in the current scope, the code

  set(VAR "" PARENT_SCOPE)

is documented to set the variable to an empty string in the parent
scope.  Fix the implementation to make it so.