Add support for determining if the newtab page changed at runtime (previously changes to newtab page were not reflected until Firefox restart)

Some bugfixes and lots of code simplification

Now adds a title prefix based on type of the tab.
Possible values are:

NewTab - your newtab page
Home - your homepage
PrivateBrowsing - default home/newtab page for privatebrowsing mode
Blank - about:blank
chromeUI - Firefox internal pages
http - insecure http pages

All other non-https urls have the protocol as prefix.