Milestone 2kb Accessibility of other solid-panes elements

[timea-solid]

There are other panes and elements that need work, too:

IMPORTANT - some panes may only be visible once Power User is active.

Solid-panes:

• SocialPane
• Prefferences together with Trusted applications (in user guide)
• Dokieli pane
• Audio pane
• Video Pane
• Slideshow Pane
• Palylist pane
• Trip Pane

TODO for each:

• adding HTML5 and ARIA labels
• add accessibility tests based on 'axe-core' (example here)
• making sure it also work when resizing screen
• making sure other accessibility features are inline with the WCAG standard (the tests will show). As example: text sizes, button sizes, keyboard focus and so on.