keep header files in their own subfolder

We have many, some with generic names, so it's probably safer this way.

CMakeLists.txt

@@ -108,7 +108,7 @@ add_library(bfps ${source_files})
 target_link_libraries(bfps ${BFPS_LIBS})
 
 install(TARGETS bfps EXPORT BFPS_EXPORT DESTINATION lib/ )
-install(DIRECTORY ${PROJECT_SOURCE_DIR}/bfps/cpp DESTINATION include/ FILES_MATCHING PATTERN "*.h*")
+install(DIRECTORY ${PROJECT_SOURCE_DIR}/bfps/cpp DESTINATION include/bfps/ FILES_MATCHING PATTERN "*.h*")
 
 #####################################################################################
 ## Export the configuration