* cleanup: moved init stuff to modest-init.[ch]

* cleanup: moved init stuff to modest-init.[ch]
* cleanup: removed the tny test account stuff; it's not needed anymore
  as the account setup works
* add some sanity checks to make sure runtime/init/singletons are really only
  started once
* fixed the appname problem: g_set_application_name should be called *after* gtk_init
* made appname platform specific; for product we will call it "Email", otherwise it will be knows as "modest"

pmo-trunk-r1623