Make burst window system partially (some codes are not tested)
Add test for engine
Rename get_batch_results to get_batches
Implement is_bursted_at
Add test for burst_result
Fix reusing prev burst_weight
Implement result_storage without mix
Add test for burst_result
Fix wscript
Add prototype for aggregator
Modify parameter of input_window's ctor
Add swap to input_window
Fix parameters of aggregator::flush_result
Add window_intersection
Use non-member get_intertection for burst_result
Remove unnecessary functions from result_window
Implement aggregator
Add test for aggregator
Add max_stored option to aggregator
Add comparing function to burst_result