Move two deprecated functions to deprecated.c.

* subversion/libsvn_subr/deprecated.c
  (svn_handle_error,
   svn_handle_warning): Move here...

* subversion/libsvn_subr/error.c
  (svn_handle_error,
   svn_handle_warning): ... from here.


git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1618849 13f79535-47bb-0310-9956-ffa450edef68