First realease of general stream slicing support for count windows

This is the first version of Scotty with in initial support of count windows.
In upcoming releases we will extend Scotty with further features from our EDBT 2019 paper on Efficient Window Aggregation with General Stream Slicing.

First release of the Scotty window processor

This is the first release of the Scotty window processor. Scotty is a high throughput operator for window discretization and aggregation. Scotty splits streams into non-overlapping slices and computes partial aggregates per slice. These partial aggregates are shared among all concurrent queries with arbitrary combinations of tumbling, sliding, and session windows.