On the 'move-tracking-2' branch: Change the editor API so that the branch is
specified explicitly by each action instead of having a 'main' branch for
the whole edit.

* BRANCH-README
  Remove the 'todo' item.

* subversion/include/private/svn_editor3.h,
  subversion/libsvn_delta/compat3.c,
  subversion/libsvn_delta/editor3.c,
  subversion/svnmover/svnmover.c
  As above.

git-svn-id: https://svn.apache.org/repos/asf/subversion/branches/move-tracking-2@1638822 13f79535-47bb-0310-9956-ffa450edef68