Nuget Migration
Update build.sh to be executable on CI server
Build subprojects
Remove targets
Attempt nuget package restore (with retry)

(With thanks to SteamKit2's developers)
Adding in missing SolutionDirParsed
Missing using
Another try to fix the ClientMsgProtobuf error in CI builds
Set protobuf to use package version that Steamkit2 was compiled with (2.0.0.621)
Autodownload NuGet.exe on build in VS.

This commit will work on Windows machines. Still looking for a fix for Mono

[ci skip]
Remove NuGet.exe from sln
Download nuget.exe
Download to the correct directory
Updates to force Mono3
Add appropriate flags to apt commands
Move mozroot certificate update to before mono install
New order
Another order change
Quickfix - GenericInventory.cs

Fixed: incorrect indexing due to class_instance.instaceid being NULL.
Source: @narugo
Merge pull request #455 from gabrielmtzcarrillo/SteamInventory

Quickfix - GenericInventory.cs