Align timing of captions with show/hide controls.

This is a re-work of https://github.com/johndyer/mediaelement/pull/358
Update src/js/mep-feature-progress.js

when dragging the playhead horizontally off the video, it will snap to the left or right
Add mejs-long-video class when capture is 1hr or longer, custom styles
Fixed attributes for PluginMediaElement

Before the attributes were written to the prototype and then all elements on one page had the attributes of the last element.
Make rewinding at the end optional
Merge pull request #725 from simonschuh/autorewind

Make rewinding at the end optional
Merge pull request #722 from simonschuh/patch-1

Bugfix: attributes for PluginMediaElement
Merge pull request #715 from catturavideo/bugfix/timefloat

Well done, sir!
Merge pull request #711 from selgas/master

Fix for dragging playhead horizontally off the video
Merge pull request #708 from rickharris/master

Align timing of captions with show/hide controls.
Add loop to build
Remove white space and extra blank lines.
Build it.
Remove whitespace.
Retab.
Ignore build