changes from jake@acutex.net to make it possible to toggle the default value of newemailtech for new profiles, this is set by default to be turned on (the old default was off) ; r=dmose@mozilla.org.  changes from me to make newemailtech the default in all new installations, and update the verbiage in various spots to make it clear that newemailtech is now considered the one true way and the old tech will be going away.  r=endico@mozilla.org,cyeh@bluemartini.com