A PHP extension wrapper for the C hdrhistogram API

HdrHistogram: A High Dynamic Range Histogram. A Histogram that supports recording and analyzing sampled data value counts across a configurable integer value range with configurable value precision within the range. Value precision is expressed as the number of significant digits in the value recording, and provides control over value quantization behavior across the value range and the subsequent value resolution at any given level.

- Migrate from resource to object of new HdrHistogram\Histogram class
- add HdrHistogram\Iterator and HdrHistogram\Iterator\Percentile classes