Adding debugging messages for Video player.

For now outputting main flow of loading YouTube or non-YouTube videos.
Addressing Anton's comments on PR 869.

Removed extra check for console.log() existance. Modified error
messages. Formatted entire file to fit in 80 lines or less.

Formatting files so that they fit under 80 lines. Adding debug info for
what type of YouTube video player is being used. Also comment on whether
playbackRates is available for HTML5 mode.

Changed back Anton's original function _checkPlaybackRates(). Now logging for
this function's result is done only on error (in the function that is invoking)
it).
Merge pull request #869 from edx/valera/video_js_console_log_useful_debug_info

Adding debugging messages for Video player.