Implement basic error classes based on Throwable::Error
Add load tests for Error classes
Add in the simple configs referenced in the author_tools readme
Trap error states and throw appropriate exceptions for the Redis storage backends
Add documentation for the new error classes (and also for the main interface role for storage backends)
Modify the MySQL backend to not reference 'master' connections. We will add that later when we need it
update the test code to match recent changes