Merged big part for linux

CMakeLists.txt

common/cpp/CMakeLists.txt

common/cpp/include/common/error.h

common/cpp/include/system_wrappers/io.h

common/cpp/include/system_wrappers/system_io.h

common/cpp/include/unittests/MockIO.h

common/cpp/src/system_io.cpp

common/cpp/src/system_io/CMakeLists.txt

common/cpp/src/system_io/has_io.cpp

common/cpp/src/system_io/system_io.cpp

common/cpp/src/system_io/system_io_linux.cpp

common/cpp/unittests/MockIO.h

common/cpp/unittests/json_parser/test_json_parser.cpp

examples/producer/dummy-data-producer/CMakeLists.txt

examples/worker/CMakeLists.txt

examples/worker/getnext_broker/getnext_broker.cpp

examples/worker/process_folder/process_folder.cpp

producer/api/CMakeLists.txt

producer/api/src/producer_impl.cpp

producer/api/unittests/test_producer_impl.cpp