Remove the fixed background, as it's causing reflows.

Scrolling on large lists of shows or episodes should be much faster now.
Use CSS instead of janky JS to turn a TD into a clickable space. Resolves browser differences and in the end is much simpler+cleaner.
Merge pull request #757 from timdorr/development

Speed up scrolling
Merge pull request #761 from thezoggy/dev--fix_tableclick

Use CSS instead of JS for table click.