Split HTML report into several parts.

[ryzhyk]

The ddshow report consists of several parts, including the timeline, which can take a very long time to load in the browser. @Kixiron suggested disabling timeline generation using the --disable-timeline switch. Alternatively, ddshow could produce a separate HTML document for each part of the report, with an index page to navigate between them, so one would only need to wait for the timeline to load if they are actually interested in looking at it.