Factor the svn_stringbuf_t and svn_membuf_t implementation to a common code base.
Factor the svn_stringbuf_t and svn_membuf_t implementation to a common code base.

* subversion/libsvn_subr/string.c (membuf_create, membuf_ensure): New, private
   helper functions for membufs and stringbufs.
  (svn_membuf__create): Call membuf_create.
  (svn_membuf__ensure): Call membuf_ensure.
  (svn_membuf__resize): Call membuf_ensure for resizing the buffer.
  (my__realloc): Remove.
  (create_stringbuf): Remove. Inline implementation into the single call.
  (svn_stringbuf_createv): Inline the previous contents of create_stringbuf.
  (svn_stringbuf_create_ensure): Call membuf_create to allocate the buffer.
  (svn_stringbuf_ensure): Call membuf_ensure to resize the buffer.


git-svn-id: f8a4e5e023278da1e04e203c7fe051e3c4285d88@1413482 13f79535-47bb-0310-9956-ffa450edef68

YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion