Debian packaging with Git notes

I finally found the time today to update my notes on how I package for Debian using Git. They're rather long (even after dropping my beginner Git tutorial, which seemed pointless given how many good ones there are now), so I'm not including the full text here. Take a look if you're curious.

The major differences from the previous version (last revised in 2012, and originally written in 2008) are:

• Standardize on the DEP-14 branch layout, which makes keeping upstream development and Debian packaging in the same repository less of a special case.

• Document the gbp pq workflow for maintaining patches against upstream instead of the mess of feature branches and merge workflow I was trying to use before. This is much simpler once one gets used to it, and allows using the 3.0 (quilt) package format as intended.

• Use dgit for the final build and upload to Debian.

• Modernize the git-buildpackage commands and remove some old workarounds that are no longer needed.

On my current development machine, I'm experimenting with using btrfs as the root file system, including using sbuild instead of pbuilder to build packages since it can use btrfs snapshots. So far, I'm extremely happy with that configuration. It was hard to find good documentation for the process, so I wrote up how I configure sbuild with btrfs in case it's of interest to anyone else. It's noticably faster than using pbuilder, and once I got used to it I think it feels a bit cleaner.