This commit
- adds 2 utility functions to the uitour's head.js
- adds the browser_UITour4.js
- moves the tests in the browser_showMenu_controlCenter.js into the newly added the browser_showMenu.js
- deletes the browser_showMenu_urlbar.js because it's test has been modified and moved into the browser_showMenu.js
- adds one test case for the page action panel in the browser_showMenu.js
- updates the browser_UITour_availableTargets.js test because we have more targets right now.
MozReview-Commit-ID: CydEAkqAl3V
