Added a columns table for storing selected columns from an rrd file also renamed rrdfile to rrd_file
Added a columns table for storing selected columns from an rrd file also renamed rrdfile to rrd_file

andy3092/flexlm-monitor-rrd,andy3092/flexlm-monitor-rrd,andy3092/flexlmmon,andy3092/flexlm-monitor-rrd,andy3092/flexlmmon,andy3092/flexlmmon