Release notes 9/23/2021

JsonSerializer

DatabaseHelper. Cache property.
DB logic moved to Algo.Export
Core is .NET Standard 2.0
SS-80 Ecng.Data replaced by native API.
Studio.Core is .NET Standard 2.0
Do.Invariant

Fix alerts initialization.
Studio.Core is .NET Standard 2.0
Do.Invariant
JsonSerializer

fix Shell build

Do.Invariant
JsonSerializer

installer: fix ui hang when check updates in progress