0.5 Rlease with multiple series queries, retention policies, mixed type points

This version supports Retention policies. You can create a new retention policy, or post into existing ones, as well as query them. This version also supports querying multi series data.
There is a breaking change to GetInfluxDBStructureAsync, which now returns a custom InfluxDB object, which not only provides info about measurements, but also about tags and fields in each of them.
Now querying data which is returned in multiple series (e.g. show stats) is supported. Also supported is querying for InfluxDB server version.

FIrst non Pre-Release version

This version supports

1. Type safe representation of a point in InfluxDB time series InfluxDatapoint<T>.
2. Grouping multiple points to single write request
3. handles partial or complete rejected requests

First pre release build

This version supports
1.Creating DB
2. Querying for DB
3. Getting hierarchical structure of DB
4. Getting single series data points
5. Writing sing and multi points to DB