SuggestBox won't show all the metric names when those metrics only differ in case

[ghost]

Currently, if there exist two metrics only different in case, the latter one will NEVER get suggested on TSD's UI.

For example, the proc.meminfo.active from tcollector's procstat.py collector was mistakenly created as proc.meminfo.Active(with a capital A). Then TSD's UI will always suggest first metric ignoring there is another metric with lowercase, the only way to plot the graph is using full metric name which is a lot of inconvenient.