use get_server_uuid() call
added exception handler
some bugfixes
fixed UTC bug
rewrote graphing code
unified access to graph_config files
hide empty graphs
removed comments
added hide_zero flag
added feeder command for ipmi_checks
support HUP signal
handle multi-device graphs when empty_zero is checked
improved merge code
use has_active_rrds flag
fixed bug in update statement
handle non-mergeable rrd-results
set ipmi_interface attribute