Added event handlers to TimedItem, plumbed knowledge of them
through to Players.
Remove some eol whitespace.
Rename impl test to new naming structure.
Mostly implemented events (but not time scaling).
Partially implemented tests for events.
timing -> specified.
Mostly working events, except for nesting + iterations + playbackRate.
stuff.
Some rework of internal timing.
Fixed nested iterations with scaling bug.
Added tests to testcases.js
Applied review changes.
Fix manual-test-preset-timings.html and manual-test-step.html

These were broken by removing TimingFunction from the public API in
3b911f74ee57eb24e804eb1b742ae45cd8864b7e.
Merge pull request #294 from steveblock/timingFunctions

Fix manual-test-preset-timings.html and manual-test-step.html
Second round of review comments.
Merge pull request #287 from shans/events

Events
Fixing the exit code when testcases need updating.