Maintenance release that brings numerous minor fixes and improvements for the different parts of Hangfire.

Hangfire.Core

• Added – Allow using macro expressions like @hourly for recurring jobs (by @MuhamedAbdalla).
• Added – Show storage time in page footer when supported by storage implementation.
• Added – Show duration and latency columns separately on the Succeeded Jobs page when supported.
• Added – Show the exception column on the Deleted Jobs page when available and supported by storage.
• Changed – Reduce package size by stripping unnecessary locales in Moment.js.
• Changed – Bump Microsoft.Owin package to version 4.2.2.
• Changed – Log a warning message when a server listens to unsupported queue names (by @MuhamedAbdalla).
• Changed – Use storage time, if available, to show delay warnings in the Dashboard UI.
• Fixed – Proper rendering of generic arguments on the Job Details page (by @olivermue).
• Fixed – Language inconsistency in the Dashboard UI related to date/time description.
• Fixed – Big stack traces take too long time to be formatted.
• Fixed – Don’t throw NullReferenceException from the Scheduled Jobs page when there’s a job with missing data.
• Fixed – Don’t throw NullReferenceException from the Processing Jobs page when there’s a job with missing data.
• Fixed – CSS for Enqueued and Deleted state cards in dark theme.
• Fixed – Log errors instead of throwing an exception when a particular table can’t be cleaned.
• Fixed – Avoid logging fatal exceptions when stopping a faulting background process.
• Fixed – Don’t display checkboxes in the Dashboard UI when job details can not be fetched.
• Fixed – Scrollbars in WebKit-based browsers are now dark in dark mode.
• Project – Disable tests for netcoreapp1.0 and netcoreapp2.1 targets since they aren’t supported in AppVeyor.
• Project – Add a net6.0 target for unit tests instead of the removed ones.
• Project – Modernise projects and build environments to use the newest features.

Hangfire.SqlServer

• Changed – Avoid throwing an exception when a connection string has duplicate property names.
• Project – Disable tests for netcoreapp1.0 and netcoreapp2.1 targets since they aren’t supported in AppVeyor.
• Project – Add a net6.0 target for unit tests instead of the removed ones.
• Project – Modernise projects and build environments to use the newest features.