beecbc7cd7
* Fix join/part collapsing regressions * Simplify loop * Explain e,e * Explain return null in _renderSummary * Kill it properly * Move . to _renderSummary * Only use the first and last events to decide whether a net change has occured * Do not sort events by TS before summarising * fix loop and comment * remove data-number-events * Better explanation comment in _renderSummary * Less tortuous comment