Add new test cases for firefox
	new file:   firefox.d/404_firefox_url.pm
	new file:   firefox.d/405_firefox_localpage.pm
Remove "tab"
	modified:   firefox.d/404_firefox_url.pm
	modified:   firefox.d/405_firefox_localpage.pm
Add new test case for firefox mhtml
	new file:   406_firefox_mhtml.pm
Some minor modifications.
Add new test case for firefox tabbed browser window
	new file:   407_firefox_tab.pm
Add new test case to this script
	modified:   406_firefox_mhtml.pm
1. Add sendkey "alt-f10" to maximize the firefox window.
2. Restroe by removing profile directory(~/.mozilla/)
Minor modifications from zxdvd
	modified:   distri/opensuse/x11regression.d/firefox.d/404_firefox_url.pm
	modified:   distri/opensuse/x11regression.d/firefox.d/407_firefox_tab.pm
fixed test failure for 13.1 RC2