KAA-229: Add kaa_deque_t collection. Change log storage api to return
single record at a time (not list). Fix unit tests.
Merge branch 'c_sdk_refactoring' of https://github.com/kaaproject/kaa into c_sdk_refactoring

Conflicts:
	client/client-multi/client-c/src/log/kaa_memory_log_storage.c