Fix extension on versions of Visual Studio 2017 earlier than 15.4.4

[jcansdale]

What this PR does

• Fix extension on versions of Visual Studio 2017 earlier than 15.4.4
• Reference Microsoft.VisualStudio.Shell.15.0 version 15.0.26228
• Reference Microsoft.VisualStudio.Threading version 15.0.240

This allows the extension to continue working on versions of Visual Studio 2017 earlier than 15.4.4 (#1812 was a report from someone using Visual Studio 15.2.6).

Note, this doesn't fix either of the following (they appear to have been caused by random extension cache corruption):

• GitHub Extension broken with VS 15.7.6 #1826 GitHub Extension broken with VS 15.7.6
• SetSite failed for the package [GitHubPackage], VS 15.8 Preview 4/5 #1810 SetSite failed for the package [GitHubPackage], VS 15.8 Preview 4/5

How to test

Ideally we would be checking that the extension works with the first RTM version of Visual Studio 2017. I don't know if this is still available for download?

Fixes#1812 Error On Project Load (VS 15.2.6)

[jcansdale]

@sharwell I can't for the life of me work out why changing from:

 <packageid="Microsoft.VisualStudio.Shell.15.0"version="15.4.27004"targetFramework="net461" />
<packageid="Microsoft.VisualStudio.Threading"version="15.4.4"targetFramework="net461" />

to

 <packageid="Microsoft.VisualStudio.Shell.15.0"version="15.0.26228"targetFramework="net461" />
<packageid="Microsoft.VisualStudio.Threading"version="15.0.240"targetFramework="net461" />

Would be necessary for an extension to install correctly on Visual Studo v15.7.6. See:

• GitHub Extension broken with VS 15.7.6 #1826 GitHub Extension broken with VS 15.7.6

This fix makes sense for the person running v15.2.6, but it doesn't make sense for any of the others. 😕

Have you come across anything else like this before?

[grokys]

So does it look like this doesn't actually fix the problem and it's actually the uninstall/reinstall/update process that fixes the problem?

[jcansdale]

@grokys this fixes #1812, which was someone running Visual Studio 15.2.6. The rest were fixed by reinstalling the extension. 😭 I'll update the PR description.

[meaghanlewis]

This LGTM! Tested on VS2017 Version 15.0.26228.48.

I installed the latest release version of GHfVS ( 2.5.4.3349) which was very broken and then installed the build from this PR and all our major functionality is working again.

Thanks @jcansdale 🎉

[jcansdale]

This LGTM! Tested on VS2017 Version 15.0.26228.48.

Excellent! This sounds like a good - worst case - VM to have in reserve. 😄