* Normalize Spack Win entrypoints
Currently Spack has multiple entrypoints on Windows that in addition to
differing from *nix implementations, differ from shell to shell on
Windows. This is a bit confusing for new users and in general
unnecessary.
This PR adds a normal setup script for the batch shell while preserving
the previous "click from file explorer for spack shell" behavior.
Additionally adds a shell title to both powershell and cmd letting users
know this is a Spack shell
* remove doskeys
