The road to 1.0 (or - at least - a stable API)

We've discussed a stable API for some time, and we keep pushing back on a 1.0. I'd like to restart the discussion and try to list some action items on the things that we want to consider a "solid" API that we will guarantee.

Boring rationale:
We've been using LibGit2Sharp in Visual Studio and Team Foundation Server for a few years(!) now, with great success. So much, in fact, that we have about 10 independent groups on the VS and TFS teams using it. And of course we want to ship a single copy of LibGit2Sharp in the VS or TFS installer, so that means that all of these teams have to be on the same version.

This is becoming increasingly burdensome for us, because any time there's an API change, either the person updating LibGit2Sharp has to go and find all the people using it, fix them and hope it works or simply push it on up and put the build on the floor. (Usually the former, as it turns out that breaking the Visual Studio build is not a good career decision.)

/cc @jamill 

No files, tests, or entry points are identified. Start by reading the issue discussion and inventorying the public LibGit2Sharp API and versioning concerns; done means reaching agreement on the stable API requirements and actionable follow-up items.