support for VS2019

[zholobov]

support for VS2019 as per https://devblogs.microsoft.com/visualstudio/how-to-upgrade-extensions-to-support-visual-studio-2019/

[NPC]

@zholobov a warning is shown for SaveAllTabs: https://docs.microsoft.com/en-us/visualstudio/extensibility/synchronously-autoloaded-extensions?view=vs-2019

Migration guide: https://github.com/Microsoft/VSSDK-Extensibility-Samples/tree/master/AsyncPackageMigration

Otherwise it works for now, thank you!

[zholobov]

@NPC I'll take a look at the async loading. @eamodio are you okay with me potentially doing a PR (maybe as part of this one) for async loading?

[eamodio]

@zholobov 👍 Sounds great as long as it keeps support for at least 2017 at a minimum

[zholobov]

@eamodio after an investigation it looks like adopting async loading would require rewriting code to use new async APIs with different assumptions on threading - i.e. making sure some VS SDK API calls are made on UI thread. I don't have time now to accomplish this major rewrite.

[tejsj]

imo adding support for 2019 with whatever caveats is better than no support? The async API can be rewritten if needed later on? I think this pull request should be accepted (FYI; I have made a similar change as this pull request and are not experiencing any problems at all in VS2019)

[DanJ210]

I see that the fork from this PR has published released for 2019 support. Thank you for the work to make this extension and the work to migrate it. Really enjoy this extension and I very much missed it. That's why I was looking it up to see if I could migrate it myself but much more advanced users than I have already done so and I'm so very glad. Thanks guys/girls!

[jcreek]

Is there a plan to merge this PR in? I can see it's been several months, but the official extension on the marketplace at https://marketplace.visualstudio.com/items?itemName=eamodio.SaveAlltheTabs still only supports up to 2017.

[marty2013]

Hi guys - looking forward to vs2019 version - whats the latest ? Needs COVID testing ? ;-)