CPack: don't write internal variables to CPackConfig.cmake

The internal variables CPACK_ADDCOMP_COMPONENTS,
CPACK_ADDCOMP_STR and CPACK_ADDCOMP_UNAME were being needlessly
exported to CPackConfig.cmake.
Prefixing them with an underscore prevents this.

CPACK_ADDCOMP_STR was particularily problematic since it contains
unescaped quotes.
cmake-mode.el: drop reserved keybindings (#14576)

The keybindings added by commit 301e67e3 (cmake-mode.el: add local
keybindings, 2012-09-20) overlap the reserved C-c space:

 http://www.gnu.org/software/emacs/manual/html_node/elisp/Key-Binding-Conventions.html

Revert the commit to drop them.

Reported-by: Paul Smith <paul@mad-scientist.net>
Reviewed-by: Eric NOULARD <eric.noulard@gmail.com>
ExternalProject: Format module documentation

Manually revise the .rst format of the documentation.  Use inline
literal quotes appropriately in paragraph text.  Move the :: literal
block openers to the end of the preceding paragraphs.  Convert the
command signature documentation and examples to cmake code-block
directives.
Makefile: Remove "forbidden" flags only as a whole

Fix CMAKE_<LANG>_CREATE_SHARED_LIBRARY_FORBIDDEN_FLAGS implementation to
only remove whole flags.  Without this n the Mac we were incorrectly
removing -w from -Wno-write-strings.
CMP0037: Extend policy to reserved names and custom targets

Teach add_custom_target to check the policy too.  Extend the policy to
disallow reserved target names that we use for builtin targets like
"all".

Extend the RunCMake.CMP0037 test to cover these cases.
Merge topic 'fix-remove-forbidden-flags'

3a8f34b Makefile: Remove "forbidden" flags only as a whole
Merge topic 'cpack-internal-variables'

7621ad6 CPack: don't write internal variables to CPackConfig.cmake
Merge topic 'emacs-mode-no-reserved-bindings'

0f21261 cmake-mode.el: drop reserved keybindings (#14576)
Merge topic 'forbid-reserved-targets'

3900fcf CMP0037: Extend policy to reserved names and custom targets
Merge topic 'doc-ExternalProject-formatting'

01ecd24 ExternalProject: Format module documentation