Updated script to version 1.4.

- Switched to separate arrays for recipe names and blocking
applications.
- Organized code into functional sections.
- Added settings validation.
- Now supports multiple blocking applications per recipe. (For MS
Office updates, for example.)
- More code comments.
- Now handles non-integer parameters like "0.5" for the number of hours
between checks.
- Removed unnecessary `exit 0`s.
Readme simplification and script updates.

- Debug mode now does a true "dry run."
- Fixed various typos.
- Removed unnecessary AutoUpdate*.xml file instructions from readme.
- Removed troubleshooting steps from readme that no longer apply.
Debug mode now ignores LastAutoUpdate value.