Support wc format 10 in 'change-svn-wc-format.py':
Support wc format 10 in 'change-svn-wc-format.py':

* tools/client-side/change-svn-wc-format.py
  (LATEST_FORMATS):  Add format 10 for Subversion 1.6.
  (Entries.entry_fields):
    Add 'tree-conflicts' and 'file-externals' fields.
  (Entry.must_retain_fields):
    Convert to hash of tuples.  Extend for format 10.

Along the way, remove the assumption that all format numbers are one byte
long:

* tools/client-side/change-svn-wc-format.py
  (Entries.format_nbr, Entries.format_nbr_bytes):  New.
  (Entries.parse):
    Promote 'format_nbr' to class member (from local variable).
    Initialise 'format_nbr_bytes'.
  (Entries.write_format):
    Overwrite all bytes of the old format number.  (Without this,
    overwriting format 10 by format 9 would leave format 90.)

git-svn-id: f8a4e5e023278da1e04e203c7fe051e3c4285d88@873621 13f79535-47bb-0310-9956-ffa450edef68

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