The Page class is now responsible for executing the subpage template
rather than the index file.
Template processing has been improved with exceptions to catch 404s, or
any other template exception, which will abort the current page and
display an error document instead.
Improved database abstraction class to support insert and select queries
in various forms.
Added classes for pulling log entries back out of the database.
Updated Job class to describe a known job in the database, and added
JobStatus to track status updates on jobs.
Updated Config class to connect to the database, and load all settings
on startup.
Improved the class autoloader to support Exceptions in a single file as
a special case, and added this file.
