Add show/hide shade-time and add blink Issue #40

CSS: Added key-frames, functions and styles to blinking items.
Made shade time default to display none for consistency.

JS: Added functions to hide/show shade-time on stop/play.
Added stop/start blinking functions that encapsulate time and shade-time nodes.
Moved around play.onclick functions to compensate for progress bar flashing near the end for <1s after a song that finished.