WindFlow release 3.6.0
This new version of WindFlow provides the following main changes:
- the source code of the library has been intensively improved and re-factorized in order to avoid code duplication as much as possible and to have a better class hierarchy in several parts of the project;
- a new operator has been added with the name Ffat_Windows_GPU. It replaces the old Ffat_Aggregator_GPU operator by improving its performance a lot. Now, window-based operators running associative aggregates can be efficiently executed on GPU with out-of-order input streams.