Iginx

- Adding new policies for realistic Online serving
- Adding aggregations along both series dimension and time dimension
- Working with Python and Go clients
- Rejecting on overloading requests
- Fixing some bugs...

- A command client for SQL-like interactions.
- The JDBC support.
- Multi-version DB instance runtime support.
- MQTT support.
- A workload-aware load balancing policy.
- Two more choices for metadata management, i.e., etcd and file storage.
- Fully support TPCx-IoT tests.
- Docker deployment support.
- Basic authorization management.
- Fix metadata management for scaling process.

+ Fully support API functions of IoTDB
+ Equivalent support on InfluxDB
+ RESTful service similar to IKR
+ Extra RESTful service on:
+ Annotations
+ Grafana Interfaces
+ Fix bugs

This release supports only time series ingestion, time range-based reads, and simple aggregations. However, this release has some features that are favorable to users:
- High Scalability
- Smooth Elasticity
- Transparent Data Distribution
- Integration with Heterogeneous Databases
- Flexible Slicing and Replication