Revert "Represent git-submodule as nested projects"

This reverts commit 69998b0c6f.
Broke Android's non-gitmodule use case.

Conflicts:
	project.py
	subcmds/sync.py

Change-Id: I68ceeb63d8ee3b939f85a64736bdc81dfa352aed

subcmds/sync.py

@@ -563,31 +563,12 @@ uncommitted changes are present' % project.relpath
       to_fetch.extend(all_projects)
       to_fetch.sort(key=self._fetch_times.Get, reverse=True)
 
-      fetched = self._Fetch(to_fetch, opt)
+      self._Fetch(to_fetch, opt)
       _PostRepoFetch(rp, opt.no_repo_verify)
       if opt.network_only:
         # bail out now; the rest touches the working tree
         return
 
-      # Iteratively fetch missing and/or nested unregistered submodules
-      previously_missing_set = set()
-      while True:
-        self.manifest._Unload()
-        all_projects = self.GetProjects(args, missing_ok=True)
-        missing = []
-        for project in all_projects:
-          if project.gitdir not in fetched:
-            missing.append(project)
-        if not missing:
-          break
-        # Stop us from non-stopped fetching actually-missing repos: If set of
-        # missing repos has not been changed from last fetch, we break.
-        missing_set = set(p.name for p in missing)
-        if previously_missing_set == missing_set:
-          break
-        previously_missing_set = missing_set
-        fetched.update(self._Fetch(missing, opt))
-
     if self.manifest.IsMirror:
       # bail out now, we have no working tree
       return