Merge branch 'jn/svn-fe'

Merge branch 'jn/svn-fe'

* jn/svn-fe: (36 commits)
  vcs-svn: suppress a -Wtype-limits warning
  vcs-svn: allow import of > 4GiB files
  vcs-svn: rename check_overflow arguments for clarity
  vcs-svn/svndiff.c: squelch false "unused" warning from gcc
  vcs-svn: reset first_commit_done in fast_export_init
  vcs-svn: do not initialize report_buffer twice
  vcs-svn: avoid hangs from corrupt deltas
  vcs-svn: guard against overflow when computing preimage length
  vcs-svn: cap number of bytes read from sliding view
  test-svn-fe: split off "test-svn-fe -d" into a separate function
  vcs-svn: implement text-delta handling
  vcs-svn: let deltas use data from preimage
  vcs-svn: let deltas use data from postimage
  vcs-svn: verify that deltas consume all inline data
  vcs-svn: implement copyfrom_data delta instruction
  vcs-svn: read instructions from deltas
  vcs-svn: read inline data from deltas
  vcs-svn: read the preimage when applying deltas
  vcs-svn: parse svndiff0 window header
  vcs-svn: skeleton of an svn delta parser
  ...