[ostree] (21 commits) Non-fast-forward update to branch wip/delta2

[Colin Walters <walters src gnome org>]

The branch 'wip/delta2' was changed in a way that was not a fast-forward update.
NOTE: This may cause problems for people pulling from the branch. For more information,
please see:

 https://wiki.gnome.org/Git/Help/NonFastForward

Commits removed from the branch:

  6c067eb... WIP: Static deltas
  571518d... deltas: Add support for LZMA compression
  139bd09... deltas: Make size configurable, pack metadata objects first
  52ffedd... show: Fix segfault if we can't find an object
  4ffd335... core: Add OSTREE_COMMIT_GVARIANT_STRING
  f8fb633... delta: Move to-commit into superblock
  4db7561... delta: Print size of fallback object
  b3ba625... core: Fix uninitialized variable

Commits added to the branch:

  22ab7b3... core: Use posix_fallocate() when writing objects (*)
  5346e06... libotutil: Fix two bugs in usage of posix_fallocate() (*)
  021c4ee... show: Fix segfault if we can't find an object (*)
  959db9f... core: Add _STRING variants of GVariant object formats (*)
  3490831... otutil: Correctly add ref to bytes when creating GVariant (*)
  f040c02... libostree: Add _finish() API to async progress (*)
  006e8f0... deltas: Link to liblzma, add internal API to use it (*)
  626fc85... pull: Stay in mainloop if we're synchronously fetching URI (*)
  7cc4a20... pull: Correctly handle error state when fetching optional d (*)
  94f9ee7... pull: Add tls-client-cert-{path,key} (*)
  64b4ec6... Revert "pull: Add tls-client-cert-{path,key}" (*)
  25ad4a9... pull: Add tls-client-cert-{path,key} (if we have new enough (*)
  3c4cca0... WIP: Static deltas
  b90a720... deltas: Add support for LZMA compression
  68d5262... deltas: Make size configurable, pack metadata objects first
  00db39e... delta: Move to-commit into superblock
  d5d8147... delta: Print size of fallback object
  550048c... core: Fix uninitialized variable
  b50c286... delta: Write out object length before write calls
  e835aef... delta: Write content directly (and async), not via tmpfiles
  be41ce0... deltas: Put deltas in a checksum-prefixed subdirectory

(*) This commit already existed in another branch; no separate mail sent