Merge remote-tracking branch 'origin/development'
# Conflicts:
# library.properties
# src/callback_timer.h
# src/message_timer.h
# test/codeblocks/ETL.cbp
# test/codeblocks/ETL.depend
# test/test_callback_timer.cpp
# test/test_message_timer.cpp
# test/vs2017/etl.vcxproj.filters
