Fix decimal processing
Null values are explicitly inserted in CqlInsert queries
Protocol v3 schema change event support CSHARP-145
Merge branch 'decimal' of https://github.com/medvekoma/csharp-driver into medvekoma-decimal
Tests: More decimal values
Merge branch 'insert_nulls' of https://github.com/medvekoma/csharp-driver into medvekoma-insert_nulls
Tests: fixed linq insert null test
PoolingOptions default based on protocol version CSHARP-133

- For protocol v3: 32k concurrent requests and 1 core 2 max connections per host
- For protocol v1 and v2: 128 requests and 2 core 8 max connections per host