This refactors the targets used to build the shared framework and its .zip files. There are lots of reasons motivating this: Arcade convergence, migration to VSTS, making it easier to build this locally, etc.
Changes:
* Moves move content of build/Sharedfx.{props/targets} into eng/targets/SharedFx.Common.{props/targets}
* Update the build to produce a `runtime.$rid.Microsoft.AspNetCore.App` package (not just the one with symbols in it)
* Refactor the targets which produce .tar.gz/.zip files into separate projects in `src/Installers/`
* Refactor installers, unit tests, and the framework projects to use ProjectReference to flow dependencies between different parts of the build.
* Makes it easier to build the shared framework locally (for the inner dev loop, you can run `dotnet build -p src/Framework/Microsoft.AspNetCore.App/src/ -r win-x64`)
* Add build definition for Azure DevOps
* Put code for metapackages in a subfolder
* Update targets to prepare for submodules merging into this repo
* Add source code for windows installer
* Add source code for Debian installers
This code previously was in private repos because it had references to internal locations and drop shares. This code has been modified to remove these internal-only pieces.
Nate McMaster
Nate McMaster
Justin Kotalik