Revision 847512

Add changed-path support to svn_client_blame().  This is accomplished
by walking the log messages *backwards* in order to determine the
paths associated with each revision, and then performing the fulltext
downloading and blame aggregation *forwards*.

* subversion/libsvn_client/blame.c
  (#include "svn_path.h"): Added for svn_path_join().
  (struct rev): Changed meaning of "path" member.  Added "next" pointer,
   for maintaining chronological list of revisions.
  (struct log_message_baton): Removed diff-relevant members; diffing now
   happens after all log messages have been processed.  Added "eldest",
   which points to the head of a chronological list of revisions, and
   "path", which holds the working logical path of the file in question.
  (log_message_receiver): Removed fulltext-retrieval and diff logic; this
    functionality postponed until after all log messages are received.
    Updated comments to reflect this change.  Added functionality to
    track path changes on a per-revision basis.
  (svn_client_blame): Added logic to determine repository root URL and
    to perform the revision full-text retrieval and blame aggregation.
    Renamed several local variables.