Change all null checking expressions to use 'is null' and 'is not null'
instead of '== null' and '!= null'.
This was mostly done with sed, so code can probably be improved in many
other ways with manual inspection, but that will come over time.
Also add code to the autoformat script to automatically fix these issues in the future.
dotnet doesn't like projects within projects in the file system, because of
default inclusion behavior, where the top project will want to include the
source files for the nested projects.
There are ways around that, but the easiest is to just make sure there aren't
projects within other project directories.
Rolf Bjarne Kvinge