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>

examples/helloworld/HelloWorldData.idl

@@ -0,0 +1,9 @@
+module HelloWorldData
+{
+  struct Msg
+  {
+    long userID;
+    string message;
+  };
+  #pragma keylist Msg userID
+};