Merge branch 'jk/remote-helper-object-format-option-fix'

The implementation and documentation of "object-format" option
exchange between the Git itself and its remote helpers did not
quite match, which has been corrected.

* jk/remote-helper-object-format-option-fix:
  transport-helper: send "true" value for object-format option
  transport-helper: drop "object-format <algo>" option
  transport-helper: use write helpers more consistently

diff --cc Documentation/gitremote-helpers.txt
Simple merge

diff --cc transport-helper.c
Simple merge