[niepce] (29 commits) ...Phase 1 of Rustification: Library is now implemented in Rust.

[Hubert Figuière <hub src gnome org>]

Summary of changes:

  cfa31f5... Rust: bootstrap rustification
  0b2ad5a... fwk+rust: mostly ported exempi.cpp to Rust
  aa09363... fwk+rust: Replace gpsCoordFromXmp() by fwk_gps_coord_from_x
  2a231c0... fwk+rust: convert fwk::fraction_to_decimal() to Rust
  b6546d2... fwk+rust: better exempi tests
  e0a4a39... fwk+rust: Implement XmpMeta::keywords()
  ee1a07c... engine+rust: Keyword is now implemented in Rust
  608444e... engine+rust: LibFolder is now implemented in Rust
  784c1f0... engine+rust: FsFile is now implemented in Rust
  38d6874... engine+rust: implement LibFile in Rust
  a0158e2... engine+rust: implement FileBundle and MimeType in Rust
  85ca0e5... build+rust: properly build the Rust library
  1b11590... fwk+rust: silence unused warning for RAII
  4774d73... engine+rust: implement Library in Rust.
  9d38e96... engine: Library::Managed -> LibraryManaged
  0510c31... engine+rust: Implement the library notification
  3b7312b... engine+rust: Implement process_xmp_update_queue()
  fb3d00d... rust: update gtk-rs depedencies to release
  99713d6... engine+rust: Fix test build
  854af68... rust+fwk: implement err_out, dbg_out and dbg_assert macros
  7dfdf3b... fwk+engine+rust: Label and RgbColour in Rust
  072f196... clang-format: update to standard
  4d36f02... rust: now use library in Rust
  4a9cbd9... library+rust: fix a crash from the sqlite callback
  301bd11... rust: fix misc warnings
  65bde77... engine: Set an empty string is property return nullptr
  1ff61e4... library+rust: fix set internal metadata SQL syntax error
  d8f729f... rust+engine: fix saving keyword in XMP. Requires new exempi
  ce6d104... Phase 1 of Rustification: Library is now implemented in Rus