Improve pool usage in svn_base64_decode/svn_base64_decode streams.
Improve pool usage in svn_base64_decode/svn_base64_decode streams.

* subversion/libsvn_subr/svn_base64.c
  (encode_baton, decode_baton): Rename pool to scratch_pool.
  (encode_data, decode_data): Allocate temporary buffer from scratch_pool 
   and clear it.
  (finish_encoding_data): Allocate temporary buffer from scratch_pool and 
   destroy it.
  (finish_decoding_data): Destroy scratch_pool.
  (svn_base64_encode, svn_base64_decode): Allocate baton from pool, not 
   from subpool.


git-svn-id: f8a4e5e023278da1e04e203c7fe051e3c4285d88@1125869 13f79535-47bb-0310-9956-ffa450edef68

YueLinHo/Subversion,wbond/subversion,YueLinHo/Subversion,wbond/subversion,wbond/subversion,YueLinHo/Subversion,YueLinHo/Subversion,wbond/subversion,YueLinHo/Subversion,YueLinHo/Subversion,wbond/subversion,wbond/subversion,YueLinHo/Subversion,YueLinHo/Subversion,wbond/subversion