Tab loading algorithm

From Searchbastard

• At startup, only first tab is loaded.
• After 4 seconds, second tab is loaded.
• When a tab is selected: If the tab isn't already loaded/loading, it will load.
• Selecting a tab also causes the next two tabs to load (after the current has finished, and one at a time)

In practice, this system causes the multisearch-tab to display quickly, but also it also offers a high chance that the next tab you are going to view is already preloaded, and thus displays instantly.

The icons of loaded tabs are a little bigger than those of tabs that have not loaded.