Stop passing optparse.Values to git_superproject

Make git_superproject independent of the command line by passing
the specific value instead of requiring the caller to have an
optparse.Values object to pass in.

Flag --use-superproject and --archive as incompatible in subcmds/init.py

Change-Id: Ied7c874b312e151038df903c8af4328f070f387c
Reviewed-on: https://gerrit-review.googlesource.com/c/git-repo/+/335135
Tested-by: LaMont Jones <lamontjones@google.com>
Reviewed-by: Raman Tenneti <rtenneti@google.com>
Reviewed-by: Mike Frysinger <vapier@google.com>

subcmds/init.py

@@ -260,6 +260,9 @@ to update the working directory files.
       if opt.use_superproject is not None:
         self.OptionParser.error('--mirror and --use-superproject cannot be '
                                 'used together.')
+    if opt.archive and opt.use_superproject is not None:
+      self.OptionParser.error('--archive and --use-superproject cannot be used '
+                              'together.')
 
     if opt.standalone_manifest and (opt.manifest_branch or
                                     opt.manifest_name != 'default.xml'):