Merge branch 'rs/tempfile-wo-the-repository'

Merge branch 'rs/tempfile-wo-the-repository'

The tempfile and lockfile APIs have been refactored to stop depending
on the 'the_repository' global variable, and their callers have been
updated to use the repository-aware variants.

* rs/tempfile-wo-the-repository:
  use repo_hold_lock_file_for_update{,_mode,_timeout}() with custom repos
  tempfile: stop using the_repository
  lockfile: add repo_hold_lock_file_for_update{,_timeout}{,_mode}()
  refs/packed: use repo_create_tempfile()
  tempfile: add repo_create_tempfile{,_mode}()