Rollback to .NET 3.5 Client Profile.
Ignore backup files generated by Visual Studio.
SharpCompress update & more rollback.
Rollup to full .NET 3.5 Framework. Sorry.
Make SharpCompress .NET 3.5 Client Profile-compatible.
Since we have the chance, ignore the pfx key.

We can't compile SharpCompress otherwise.
Complete rewrite for .NET 3.5.
Remove SharpCompress from externals.

Instead use Version 0.8.2 (yep, old) from NuGet. It's the most recent version still compatible with .NET 3.5.