Merge pull request microsoft#1731: [HOTFIX] Use one NuGet feed

I pushed all of the packages we need to our custom feed. Script included.

Merge pull request microsoft#1717: [HOTFIX] Update Git to remove ODB …

…string check

See microsoft/git#306.

Merge pull request microsoft#1711: hotfix upgrade with new certificate

[HOTFIX] Fix upgrader's expectation of a single certificate

Merge pull request microsoft#1707: Merge milestones/M180 into release…

…s/shipped

The only functional behavior change is from microsoft#1706 which includes the GCM Core update.

This also includes microsoft#1703 which deleted the macOS projects, but doesn't change the Windows executable.

Merge pull request microsoft#1701: [HOTFIX] Delete all macOS projects…

… and platform code

Some macOS projects were causing failures in the release process, so
let's finally get around to deleting them.

This is the hotfix PR, but it should help with launching the VFS for Git release process.

Merge pull request microsoft#1686: [Release] Milesone M174

Major Updates
-----------------

* Comes with Git for Windows 2.28.0
* Previous builds were not including fully-signed DLLs. This is now fixed.

Pull Requests
---------------

* microsoft#1672: ProductUpgrader: be extra careful about a copy loop
* microsoft#1674: Config: disable status.submoduleSummary
* microsoft#1675: PreCommandHook: don't lock pack-objects 
* microsoft#1676: Update Git to v2.27.0.vfs.1.0 
*  microsoft#1679: BuildGVFSForWindows.bat: use nuget on PATH
* microsoft#1683: GVFS.SignFiles.csproj: include more DLLs for signing
* microsoft#1685: minor path comparison fixup in ProductUpgrader
*  microsoft#1682: Update Git to v2.28.0

Merge pull request microsoft#1678: BuildGVFSForWindows.bat: use nuget…

… on PATH when possible

Our release build is failing because we cannot download nuget due to TLS
1.2 changes. But we already require nuget.exe in an earlier step of the
build.

Require nuget.exe to be on the PATH, and update Readme.me accordingly.

Merge pull request microsoft#1673: ProductUpgrader: be extra careful …

…about a copy loop

The `ProductUpgrader` makes a backup of the `C:\Program Files\GVFS` folder before running the install, as a mechanism for backing out a failed upgrade. However, it copies that data into `C:\Program Files\GVFS\ProgramData\GVFS.Upgrade\Tools`, which can create a copy loop! This affected an actual user.

I'm not sure why this affects that one user but not another. In addition to adding more defensive programming (adding the target of the copy to the list of exclusions), I also added some extra tracing so we can see how these strings differ on this machine.

See microsoft#1672 for the master PR.

Merge pull request microsoft#1660: Update Git to include v2.26.2

Hotfix

Merge pull request microsoft#1438: [Mac kext] Allow privileged system…

… service 'amfid' to hydrate

[releases/shipped] Allow privileged system service 'amfid' to hydrate