Merge pull request #4 from c42f/master

Fix broken install when doxygen is not found

CMakeLists.txt

@@ -101,10 +101,12 @@ set(DOC_INSTALL_TARGET "share/doc/${PROJECT_NAME}/api" CACHE STRING "Target wher
 add_dependencies(${LIB_NAME} doc)
 install(FILES nabo/nabo.h DESTINATION include/nabo)
 install(FILES README.md DESTINATION share/doc/${PROJECT_NAME})
-install(DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/doc/html DESTINATION ${DOC_INSTALL_TARGET})
+if (DOXYGEN_FOUND)
+	install(DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/doc/html DESTINATION ${DOC_INSTALL_TARGET})
+endif(DOXYGEN_FOUND)
 
 enable_testing()
 
 add_subdirectory(examples)
 add_subdirectory(tests)
-add_subdirectory(python)
+add_subdirectory(python)