choco pack - smoother integration with git

At the moment choco pack is normally performed when you've built everything and you need to release package.

The git repository which is in use might be heavy and contain multiple other dlls, not only the one which you want to publish in package.

It would be good if choco can use:
1. Detect / determine in which branch it's working and perform or not perform package publishing according to it.
2. Have a built-in mechanism to automatically increment version based on what package was published on server already + version saved in .nuspec file.
3. Use git tagging + checksum over all files to detect if publishing / no publishing is required.

Start by tracing the choco pack workflow and how it reads the .nuspec file, publishes packages, and interacts with the Git working tree. Compare the three requested approaches—branch checks, server/version-based increments, and Git tags with checksums—and define which behavior should determine whether a package is published.

Written by the indexing model from the issue text.