Update README and add guidelines for CONTRIBUTING

Rename 'Readme.txt' to 'README.rst', format the documentation as
reStructuredText, and modernize the content.  Also add a new
'CONTRIBUTING.rst' explaining the preferred entry path for new
contributors.

CONTRIBUTING.rst

+Contributing to CMake
+*********************
+
+Community
+=========
+
+The preferred entry point for new contributors is the mailing list.
+Please subscribe and post to the `CMake Developers List`_ to offer
+contributions.  Regular and productive contributors may be invited
+to gain direct push access.
+
+.. _`CMake Developers List`: http://www.cmake.org/mailman/listinfo/cmake-developers
+
+Patches
+=======
+
+Please base all new work on the ``master`` branch.  Then use
+``git format-patch`` to produce patches suitable to post to
+the mailing list.
+
+License
+=======
+
+We do not require any formal copyright assignment or contributor license
+agreement.  Any contributions intentionally sent upstream are presumed
+to be offerred under terms of the OSI-approved BSD 3-clause License.
+See `Copyright.txt`_ for details.
+
+.. _`Copyright.txt`: Copyright.txt

README.rst

+CMake
+*****
+
+Introduction
+============
+
+CMake is a cross-platform, open-source build system generator.
+For full documentation visit the `CMake Home Page`_ and the
+`CMake Documentation Page`_.
+
+.. _`CMake Home Page`: http://www.cmake.org
+.. _`CMake Documentation Page`: http://www.cmake.org/cmake/help/documentation.html
+
+License
+=======
+
+CMake is distributed under the OSI-approved BSD 3-clause License.
+See `Copyright.txt`_ for details.
+
+.. _`Copyright.txt`: Copyright.txt
+
+Building CMake
+==============
+
+Supported Platforms
+-------------------
+
+MS Windows, Mac OS X, Linux, FreeBSD, Solaris, HP-UX, IRIX, BeOS, QNX
+
+Other UNIX-like operating systems may work too out of the box, if not
+it should not be a major problem to port CMake to this platform.
+Subscribe and post to the `CMake Users List`_ to ask if others have
+had experience with the platform.
+
+.. _`CMake Users List`: http://www.cmake.org/mailman/listinfo/cmake
+
+Building CMake from Scratch
+---------------------------
+
+UNIX/Mac OSX/MinGW/MSYS/Cygwin
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+You need to have a compiler and a make installed.
+Run the ``bootstrap`` script you find the in the source directory of CMake.
+You can use the ``--help`` option to see the supported options.
+You may use the ``--prefix=<install_prefix>`` option to specify a custom
+installation directory for CMake. You can run the ``bootstrap`` script from
+within the CMake source directory or any other build directory of your
+choice. Once this has finished successfully, run ``make`` and
+``make install``.  In summary::
+
+ $ ./bootstrap && make && make install
+
+Windows
+^^^^^^^
+
+You need to download and install a binary release of CMake in order to build
+CMake.  You can get these releases from the `CMake Download Page`_ .  Then
+proceed with the instructions below.
+
+.. _`CMake Download Page`: http://www.cmake.org/cmake/resources/software.html
+
+Building CMake with CMake
+-------------------------
+
+You can build CMake as any other project with a CMake-based build system:
+run the installed CMake on the sources of this CMake with your preferred
+options and generators. Then build it and install it.
+For instructions how to do this, see documentation on `Running CMake`_.
+
+.. _`Running CMake`: http://www.cmake.org/cmake/help/runningcmake.html
+
+Contributing
+============
+
+See `CONTRIBUTING.rst`_ for instructions to contribute.
+
+.. _`CONTRIBUTING.rst`: CONTRIBUTING.rst

Readme.txt

-This is CMake, the cross-platform, open-source make system.
-CMake is distributed under the BSD License, see Copyright.txt.
-For documentation see the Docs/ directory once you have built CMake
-or visit http://www.cmake.org.
-
-
-Building CMake
-==============
-
-
-Supported Platforms
--------------------
-
-MS Windows, Mac OS X, Linux, FreeBSD, Solaris, HP-UX, IRIX, BeOS, QNX
-
-Other UNIX-like operating systems may work too out of the box, if not
-it shouldn't be a major problem to port CMake to this platform. Contact the
-CMake mailing list in this case: http://www.cmake.org/mailman/listinfo/cmake
-
-
-If you don't have any previous version of CMake already installed
---------------------------------------------------------------
-
-* UNIX/Mac OSX/MinGW/MSYS/Cygwin:
-
-You need to have a compiler and a make installed.
-Run the bootstrap script you find the in the source directory of CMake.
-You can use the --help option to see the supported options.
-You may want to use the --prefix=<install_prefix> option to specify a custom
-installation directory for CMake. You can run the bootstrap script from
-within the CMake source directory or any other build directory of your
-choice. Once this has finished successfully, run make and make install.
-So basically it's the same as you may be used to from autotools-based
-projects:
-
-$ ./bootstrap; make; make install
-
-
-* Other Windows:
-
-You need to download and install a binary release of CMake in order to build
-CMake.  You can get these releases from
-http://www.cmake.org/HTML/Download.html .  Then proceed with the instructions
-below.
-
-
-You already have a version of CMake installed
----------------------------------------------
-
-You can build CMake as any other project with a CMake-based build system:
-run the installed CMake on the sources of this CMake with your preferred
-options and generators. Then build it and install it.
-For instructions how to do this, see http://www.cmake.org/HTML/RunningCMake.html