Includes PHPDoc license tag in the file-level block with accompanying copyright notice.
Also added an AUTHORS file on the off chance of outside contributions
This method provides generalized, consistent type casting more versatile than PHP's basic type juggling while hiding the significant complexity in achieving this.
While this commit does not change any existing code to use the new method, the intent is for both API handlers and database drivers to use the same basic rules for type conversion while still allowing for differing failure modes.
