Web Replay: improve logging of event loop inputs, DOM events, top-level JS function calls, memoized inputs.

This change adds logging for top-level JavaScript functions. It also
adds proper indentation, making the causality between the above input
types visually apparent.
Fix misplaced ENABLE(WEB_REPLAY) guards that broke non-Timelapse builds.
Add guards for non-debug builds in InspectorReplayAgent.
Fix double-initialization and other nondeterminism regressions in DOMTimer.

Closes #358.
Update README.md to point to wiki locations instead of external project page.
Update the public nightly builder script to work with WebInspectorUI.