Background: In 1.1, we had added some logic in the nuspec reader that detect if the <metadata> tag has a schemaVersion attribute (e.g. <metadata schemaVersion="2">), and tells you to upgrade NuGet if it does. This is
not a ‘proper’ XML versioning story, but we’ll still try to make use of it since that’s all we have in 1.1.
So the plan is:
In 1.2, all new packages created we have this schemaVersion="2" flag, so that 1.1. clients will be asked to upgrade
In 1.3, we will switch to a more correct versioning scheme using the xmlsn schema. E.g. <package xmlns="http://schemas.microsoft.com/packaging/2011/06/nuspec.xsd">