Reorganize repository

* Move the project top-level CMakeLists.txt to the root of the project;
  this allows building Cyclone as part of ROS2 without any special
  tricks;

* Clean up the build options:

  ENABLE_SSL:    whether to check for and include OpenSSL support if a
                 library can be found (default = ON); this used to be
                 called DDSC_ENABLE_OPENSSL, the old name is deprecated
                 but still works
  BUILD_DOCS:    whether to build docs (default = OFF)
  BUILD_TESTING: whether to build test (default = OFF)

* Collect all documentation into top-level "docs" directory;

* Move the examples to the top-level directory;

* Remove the unused and somewhat misleading pseudo-default
  cyclonedds.xml;

* Remove unused cmake files

Signed-off-by: Erik Boasson <eb@ilities.com>

docs/manual/GettingStartedGuide/next_steps.rst

@@ -0,0 +1,43 @@
+..
+   Copyright(c) 2006 to 2018 ADLINK Technology Limited and others
+
+   This program and the accompanying materials are made available under the
+   terms of the Eclipse Public License v. 2.0 which is available at
+   http://www.eclipse.org/legal/epl-2.0, or the Eclipse Distribution License
+   v. 1.0 which is available at
+   http://www.eclipse.org/org/documents/edl-v10.php.
+
+   SPDX-License-Identifier: EPL-2.0 OR BSD-3-Clause
+
+.. _`WhatsNext`:
+
+.. raw:: latex
+
+    \newpage
+
+############
+What's next?
+############
+
+Want to know more about DDS?  The primary source of information is the
+OMG website at http://www.omg.org and specifically the `DDS Getting
+Started <http://www.omg.org/gettingstarted/omg_idl.htm>`_ page and the
+`DDS specification <http://www.omg.org/spec/DDS/>`_ itself. The
+specification is a bit wordy and of course deals with minute details,
+but it is surprisingly easy to follow for a specification.
+
+There are also various resources on the web dealing with DDS in general,
+as the various vendors have posted tutorials, presentations, general
+information and documentation on their products. While the details
+between the various implementations do differ, they have much more in
+common than what separates them, and so this information is also
+applicable to Eclipse Cyclone DDS. The one thing in which
+Eclipse Cyclone DDS really differs is in the details of API, but that's
+just syntax.
+
+Obviously there are also things specific to Eclipse Cyclone DDS. The
+level of documentation of Eclipse is not nearly what it should be, but
+that will improve over time.
+
+And last but note least: please always feel welcome to ask questions on
+GitHub!