* fix segment underReplicated/unavailable counts to be gauges instead of counters
* fix jvm/gc/cpu to be a counter instead of timre
jvm/gc/cpu represents the total cpu time spent for multiple gc
invocations, not the time spent in each gc cycle.
the number needs to be divided by jvm/gc/count to get the average gc
time per cycle
* update docs
* fix spellcheck