Revision 75285

- remove a duplicate instance of user_pref("browser.startup.homepage"
- remove user_pref("browser.ctrlTab.previews", true); and go with upstream default
- add user_pref("browser.showQuitWarning", true);
SILENT: rationale about user_pref("browser.showQuitWarning", true); :
SILENT: o without that dialogue users may be confused whether the session was saved or not
SILENT: o upstream offers a big "restore previous session" button in the about:home page
SILENT:   (the default upstream home page); since the default home page in Mageia
SILENT:   redirects to Mageia.org the situation is much worse without that pref set to
SILENT:   true as that button won't be visible on first look for users (it exists in the
SILENT:   History menu, which is not exactly the first place users will look)