Make export selection consistent between platforms and allow selecting which projects to export (#789)

* Experimenting with tests

* Overhaul handling of paths for pack files to always use standardized style

Also allows disabling export of all items

* Minor improvements

* Revert test things

* Minor tweaks

* Fix clippy warning

theseus/src/lib.rs

@@ -22,4 +22,5 @@ pub use api::*;
 pub use error::*;
 pub use event::{EventState, LoadingBar, LoadingBarType};
 pub use logger::start_logger;
+pub use state::InnerProjectPathUnix;
 pub use state::State;