Make API docs more usable on mobile browsers

Mobile browsers such as Safari on iPhone or Chrome on Android phones use very small fonts for some parts of javadoc generated API docs, while other parts are displayed in larger/normal font size. Affected parts include the navigation bar, certain type links, summary tables and parameter and exception clauses in member signatures (see attached pictures).

This is caused by browsers on devices with smaller screens use a viewport to scale web pages that are not optimized for mobile use. The solution is probably to use the viewport meta tag [1] in combination with CSS media queries [2] to make javadoc generated pages display well on devices with smaller screens.

[1] https://developer.mozilla.org/de/docs/Mozilla/Mobile/Viewport_meta_tag
[2] https://developer.mozilla.org/en-US/docs/Web/CSS/Media_Queries