Works around Xcode relative path bug.

Xcode has an issue with files located above the folder where a project file is located. The problem appears when trying to navigate to a test failure file/line combination in one of these files.  Xcode can parse the filename, but cannot navigate to the actual line number.  By reorganizing the folders I was able to get around this issue.

Also moves the shared schemes back into the xcworkspace.
Add scheme for testing the library.