0.13.0 - External Encoding support + other fixes

Improvements:

• #89 - Add support for external EncodingProviders - read this wiki page for details

Bug fixes:

• #51, #59, #62 - Fix some issues uncovered by the linq2db/linq2db team
• #78 - Emit InfoMessage events when the driver receives messages from the server
• #86 - Allow DbProviderFactory use in .net core 2.0 and standard 2.0
• #90 - Add some robustness around handling of environment-change tokens sent from the server
• #92 - Expose AseConnection.ClearPools() static stub. Note: much like the close-doors button in a lift, this function is not implemented (nor is ClearPool)

Other:

• #43 - Improve CodeFactor grades

Note: if you see a 0.12.0 release on NuGet, do not use it. The assembly version was unintentionally upped, so we trashed that release number.