Deprecate svn_fs_commit_txn in favour of svn_fs_commit_txn2.

* subversion/include/svn_fs.h
  (svn_fs_commit_txn): Deprecate.

* subversion/libsvn_repos/fs-wrap.c
  (svn_repos_fs_commit_txn): Call newer function.

* subversion/libsvn_fs/editor.c
  (svn_fs__editor_commit): Call newer function.


git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1546032 13f79535-47bb-0310-9956-ffa450edef68