GitLab

- Fix for API changes
- This remove an indirect duplicate incompatible bitflags

- don't use once_cell::Lazy
- remove lot of unsafe
- add # Safety documentation as needed

- Use cargo workspaces

- no longer use the fork
- update other rust crates with cargo update

- remove thumbnail notifications and merge them with lib notifications

- also added is_unknown() method
- no longer uses gio_sys
- fix a bug where guess_type_for_file() would call itself

- remove unused exports
- remove use of transmute()

- Also remove the corresponding C++ code.
- Compile resources for pure Rust (examples)

- This allow to use the Rust cell renderer
- remove the C++ cell renderer

- still not used
- tweak the model a bit to match
- Change the prototype of the get_colour callback

- this caused the label to not be stored properly in the DB

- rename ThumbNav
- added a widget-test example

- use an inclusive bound in the loop