* Updated Alert->register() to take message variables using the 'variables' parameter.
* Added a 'cache' parameter to Database->insert_or_update_health() and ->insert_or_update_temperature(). When set, the SQL UPDATE/INSERT calls and pushed into the array reference set in 'cache'. This is to allow performance improvements when processing a large amount of sensor/device data.
* Updated Log->variables() to take a 'prefix' parameter that, when set, will prefix the string to each variable line.
* Updated scan-ipmitool to use Database->insert_or_update_health() and ->insert_or_update_temperature().
Signed-off-by: Digimer <digimer@alteeve.ca>
