Search in one tab affects another

[denispeplin]

Steps to reproduce:

1. Open http://voltframework.com/docs in two tabs
2. Search for some word in the tab one. For example, word 'prefix'. Navigation tree in this tab will shrink.
3. Switch to the other tab, select any menu item in the navigation tree. An according page will be displayed correctly, but navigation tree will shrink too, and search word from other tab will be displayed in search box.