Help: move DESTDIR into a separate page

Help/envvar/DESTDIR.rst

@@ -0,0 +1,19 @@
+DESTDIR
+-------
+
+On UNIX one can use the ``DESTDIR`` mechanism in order to relocate the
+whole installation.  ``DESTDIR`` means DESTination DIRectory.  It is
+commonly used by makefile users in order to install software at
+non-default location.  It is usually invoked like this:
+
+::
+
+ make DESTDIR=/home/john install
+
+which will install the concerned software using the installation
+prefix, e.g.  ``/usr/local`` prepended with the ``DESTDIR`` value which
+finally gives ``/home/john/usr/local``.
+
+WARNING: ``DESTDIR`` may not be used on Windows because installation
+prefix usually contains a drive letter like in ``C:/Program Files``
+which cannot be prepended with some other prefix.

Help/index.rst

@@ -29,18 +29,18 @@ Reference Manuals
    /manual/cmake-commands.7
    /manual/cmake-compile-features.7
    /manual/cmake-developer.7
+   /manual/cmake-env-variables.7
    /manual/cmake-generator-expressions.7
    /manual/cmake-generators.7
    /manual/cmake-language.7
-   /manual/cmake-server.7
    /manual/cmake-modules.7
    /manual/cmake-packages.7
    /manual/cmake-policies.7
    /manual/cmake-properties.7
    /manual/cmake-qt.7
+   /manual/cmake-server.7
    /manual/cmake-toolchains.7
    /manual/cmake-variables.7
-   /manual/cmake-env-variables.7
 
 .. only:: html or text
 

Help/manual/cmake-env-variables.7.rst

@@ -16,6 +16,7 @@ Environment Variables that Control the Build
    /envvar/CMAKE_CONFIG_TYPE
    /envvar/CMAKE_MSVCIDE_RUN_PATH
    /envvar/CMAKE_OSX_ARCHITECTURES
+   /envvar/DESTDIR
    /envvar/LDFLAGS
    /envvar/MACOSX_DEPLOYMENT_TARGET
 

Help/variable/CMAKE_INSTALL_PREFIX.rst

@@ -10,21 +10,7 @@ See :variable:`CMAKE_INSTALL_PREFIX_INITIALIZED_TO_DEFAULT` for how a
 project might choose its own default.
 
 On UNIX one can use the ``DESTDIR`` mechanism in order to relocate the
-whole installation.  ``DESTDIR`` means DESTination DIRectory.  It is
-commonly used by makefile users in order to install software at
-non-default location.  It is usually invoked like this:
-
-::
-
- make DESTDIR=/home/john install
-
-which will install the concerned software using the installation
-prefix, e.g.  ``/usr/local`` prepended with the ``DESTDIR`` value which
-finally gives ``/home/john/usr/local``.
-
-WARNING: ``DESTDIR`` may not be used on Windows because installation
-prefix usually contains a drive letter like in ``C:/Program Files``
-which cannot be prepended with some other prefix.
+whole installation. See :envvar:`DESTDIR` for more information.
 
 The installation prefix is also added to :variable:`CMAKE_SYSTEM_PREFIX_PATH`
 so that :command:`find_package`, :command:`find_program`,