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>

.travis.yml

@@ -165,7 +165,7 @@ script:
           -DUSE_SANITIZER=${ASAN}
           -DBUILD_TESTING=on
           -DWERROR=on
-          -G "${GENERATOR}" ../src
+          -G "${GENERATOR}" ..
   - ${SCAN_BUILD} cmake --build . --config ${BUILD_TYPE} --target install
   - CYCLONEDDS_URI='<CycloneDDS><DDSI2E><Internal><EnableExpensiveChecks>all</EnableExpensiveChecks></Internal></DDSI2E></CycloneDDS>' ctest -T test -C ${BUILD_TYPE}
   - if [ "${ASAN}" != "none" ]; then