Modify markup for progressbar

- Delete 'hard-coded' style-tag (width 100%) from markup for outer wrapper '.container' in player.js, because it's already styled by that class in _theme.scss
- Add class '.progress' to the outer container <progress>
- Add an inner div-element within the progress-element for the inner progressbar (class 'meter')
First styling of progressbar

- Define color-variables for elements in progressbar
- Set general positions for inner and outer progressbar
- Minor fix in titlebar for button bigplay: Decrease height
fixes progressbar setting for min/max