Provide a default IAppSetup in the case that the author didn't
Provide a default IAppSetup in the case that the author didn't

In the case that the package author didn't follow directions, and none of
their EXE files have IAppSetup implementations, create a default IAppSetup
for every EXE file in the package.

rzhw/Squirrel.Windows,rzhw/Squirrel.Windows