Database: comment on $log object picking up root logger
Database: issue #95; use dot notation for 'type' in errors
project: add comments about using get_logger for root logger
Database: close #94; added is_connected() method

- 'is_connected()' returns true if $dbh has already been set up via
  connect(), or an Error object if not
- Added calls to 'is_connected()' in all of the methods that use the
  classwide $dbh database handle
Database: added POD header and footer

- Started to add an example of using the module in SYNOPSIS