implemented retrieving data from given fileinfo

tests/automatic/worker/worker_api/check_linux.sh

tests/automatic/worker/worker_api/check_windows.bat

tests/automatic/worker/worker_api/worker_api.cpp

tests/automatic/worker/worker_api_python/check_linux.sh

tests/automatic/worker/worker_api_python/check_windows.bat

tests/automatic/worker/worker_api_python/worker_api.py

worker/api/cpp/include/worker/data_broker.h

worker/api/cpp/src/folder_data_broker.cpp

worker/api/cpp/src/folder_data_broker.h

worker/api/cpp/src/server_data_broker.cpp

worker/api/cpp/src/server_data_broker.h

worker/api/cpp/unittests/test_folder_broker.cpp

worker/api/python/asapo_worker.pxd

worker/api/python/asapo_worker.pyx.in