Instead of using `dotnet publish`, we can use `dotnet build` and the new
`netcoreapp1.0` framework with a new dependency on
`Microsoft.NETCore.App` to generate output that does not include the
runtime, but can be run anywhere (given the installation of the
runtime).
While we cannot yet adopt a dependency on the shared host until .NET
Core RTM, we are forced to switch to this system anyway because the
latest RC3 packages and CLI do not support `netstandardapp1.5`. See
dotnet/cli#2482.
Thus we're in an in-between state where we have to use `netcoreapp1.0`,
but cannot use `"Microsoft.NETCore.App": { "type": "platform" }` to
utilize the shared host, as we need to continue to ship our host.
Without specifying "platform", we retain the status quo with respect to
build steps and outputs.
Additionally, there is no longer a good reason to use the RC3 packages,
and it has been advised we switch to RC2 since the
`Microsoft.NETCore.App` is only available for RC2. We must update
packages because our current version can no longer be debugged.
The primary reason to do this is that the VS Code debugger is not
compatible with rc2.
Secondarily, we want to continue tracking CoreCLR/FX master branch,
which means to continue with the latest release candidates. Since we are
releasing in August, we will be able to pick up the converged RTM
version before release.
The only advantage of rc2 is that it is frozen; but we have this anyway
because we snap to particular builds.