Renamed POD test to match numbering format.
Adding test to verify module compilation.
Adding MANIFEST completeness test.
Marked which tests are still pending.
Add Test::Exception to the list of modules required for testing.
Add File::Temp to the list of modules needed for testing.
Added a test suite to check handling of numbers.
No idea why those types were commented out.
Subclasses need to `use` their base classes.
We require Scalar::Util.
Properly set and get the value when testing.
Many changes related to the tied hash!

* Add a circular reference to the tied hash, giving us access to the
enclosing instance.
* Use access to the enclosing instance when pulling the list of keys.
* Setting a key to undef no longer deletes the key.
* Create a separate package for the tied hash, to keep namespaces
cleaner.
Remember, testing for false is NOT defined()
Put in the correct range of numbers, depending on platform native
integer type.
Remove XML::AppleConfigProfile::Profile until it's added to the
repository.
Remove the ::Common where it's not supposed to be.
Replace $Payload with $Profile, and only import the $Profile* symbols we
need.
Wow, ::Common really got in everywhere!
We have a test suite for numbers!
Replaced U< with I< in POD