SelectLibraryConfigurations: Do not cache the _LIBRARY variable

SelectLibraryConfigurations module currently cache and mark as advanced
the variable ${basename}_LIBRARY.
${basename}_LIBRARY_RELEASE and ${basename}_LIBRARY_DEBUG are usually
cached, because they often come from find_library().
${basename}_LIBRARY on the other hand is always of type
"optimized;${${basename}_LIBRARY_RELEASE};debug;${${basename}_LIBRARY_DEBUG}"
or just "${basename}_LIBRARY_RELEASE" or "${basename}_LIBRARY_DEBUG" if
only one version of the library is not found, if both have the same
value, or if configuration types are not supported.

Caching and marking as advanced just ${basename}_LIBRARY_RELEASE and
${basename}_LIBRARY_DEBUG is enough, just by modifying these two
variables, the user has enough control on finding the library, and
having 3 variables is redundant and confusing.
OS X: Enable rpath support on Mac OS X when find_library() is used.
MinGW: Find mingw32-make included with Code::Blocks IDE (#14302)

If one installs MinGW using the Code::Blocks IDE installer it goes to a
path like "c:\Program Files\CodeBlocks\MinGW", not "c:\MinGW".  Use the
CodeBlocks registry entry to get the location.

Signed-off-by: Jason Spiro <jasonspiro4@gmail.com>
CPackWIX: Handle CPACK_PACKAGE_EXECUTABLES (#13967)

Add start menu items including an uninstall shortcut.  Add variable
CPACK_WIX_PROGRAM_MENU_FOLDER to configure folder name.
CPackWIX: Fix MSI package layout regression from parent

The parent commit added a regression where if the install directory had:

  parent
    child A
    child B

the produced MSI would install:

  parent
    child A
       child B
CPackWIX: Handle multiple shortcuts in the start menu
CPackWIX: Add option to specify the language(s) of the installer

Add option "CPACK_WIX_CULTURES".
CMakeCPack: Provide an upgrade guid for WiX

Set CPACK_WIX_UPGRADE_GUID.  Without this upgrade GUID, you end up with
multiple instances of the same installation when installing cmake from a
WIX generated installer.
CPackWIX: Add support for custom WiX templates

WiX provides a lot of functionality for installers that cannot be
supported (easily) in the default WIX.template.in file.

For most users, the default template should be fine.  However if users
want to produce merge modules, include custom actions, etc, this new
option allows for a hook into how the wxs is produced.
ExportTargets: add one more comment to the generated file.

This patch adds a comment above the block which protects
the exported targets file against multiple inclusion, to make
the file easier to understand for readers.

Alex
CMake Nightly Date Stamp
SelectLibraryConfigurations: Use -NOTFOUND instead of copying the vars

If one of the libraries (_DEBUG or _RELEASE) is not set, the value is
set to the value of the other one.  FindQt4, from which the macro is
extracted, sets the values to XXX_LIBRARY_{DEBUG,RELEASE}-NOTFOUND
instead.  In both cases the XXX_LIBRARY is correct, but using NOTFOUND
makes it easier to understand which one is missing.

Update Tests/CMakeOnly/SelectLibraryConfigurations with the new logic.
OS X: Fix regression handling frameworks for Ninja

Fix a regression created by commit 373faae5 (Refactor how bundles and
frameworks are supported, 2013-05-05).

Since the ninja file isn't aware of how framework symlinks work, we
suppress symlink creation and let cmOSXBundleGenerator handle it.  Also,
use the real name of framework library in build rules as was done
before, instead of the symlink.
Merge topic 'mingw-in-codeblocks'

9cdc5e6 MinGW: Find mingw32-make included with Code::Blocks IDE (#14302)
Merge topic 'cpack-wix'

bf23891 CPackWIX: Add support for custom WiX templates
155bb01 CMakeCPack: Provide an upgrade guid for WiX
bfa2e29 CPackWIX: Add option to specify the language(s) of the installer
6e51ea9 CPackWIX: Handle multiple shortcuts in the start menu
6d77e1a CPackWIX: Fix MSI package layout regression from parent
8c0e325 CPackWIX: Handle CPACK_PACKAGE_EXECUTABLES (#13967)
Merge topic 'SelectLibraryConfigurations'

04d4dc3 SelectLibraryConfigurations: Use -NOTFOUND instead of copying the vars
07b44e7 SelectLibraryConfigurations: Do not cache the _LIBRARY variable
Merge topic 'rpath-on-mac'

603bc59 OS X: Fix regression handling frameworks for Ninja
e645ff0 OS X: Enable rpath support on Mac OS X when find_library() is used.
Merge topic 'AddCommentsToExportsFile'

4b1919f ExportTargets: add one more comment to the generated file.