added missing BUILD_EXAMPLES option for cmake

CMakeLists.txt

@@ -10,6 +10,7 @@ ENDIF(WIN32)
 option(BUILD_TESTS "Uses googletest to build tests" OFF)
 option(BUILD_INTEGRATION_TESTS "Include integration tests (CMAKE >3.7 is needed)" OFF)
 option(BUILD_DOCS "Uses doxygen to build the documentaion" OFF)
+option(BUILD_EXAMPLES "Build examples" OFF)
 
 set(CMAKE_MODULE_PATH ${PROJECT_SOURCE_DIR}/CMakeModules/)