Get rid of the -Wdeprecated-declarations usage warning for svn_fs_hotcopy2().

For consistency's sake, move all existing libsvn_fs compatibility wrappers
(e.g. svn_fs_hotcopy() or svn_fs_begin_txn()) into the new 'deprecated.c'
file.  Do not touch non-trivial (depending on other static functions or
directly calling the vtable members) deprecated functions, e.g svn_fs_new().
We cannot move them without actually changing the code and they do not
trigger deprecation warnings, so just leave them as is.

* subversion/libsvn_fs/access.c
  (svn_fs_access_add_lock_token): Move this ...

* subversion/libsvn_fs/fs-loader.c
  (svn_fs_upgrade, svn_fs_hotcopy2, svn_fs_hotcopy,
   svn_fs_begin_txn, svn_fs_change_rev_prop, svn_fs_get_locks): ...and these
    deprecated functions ...

* subversion/libsvn_fs/deprecated.c
  (svn_fs_upgrade, svn_fs_hotcopy2, svn_fs_hotcopy,
   svn_fs_begin_txn, svn_fs_change_rev_prop, svn_fs_get_locks,
   svn_fs_access_add_lock_token): ...into this new file.


git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1615528 13f79535-47bb-0310-9956-ffa450edef68