Update to glib 0.14

An intimidating spam of compiler errors at the start, but the
biggest was handling the new convention of `ostree_sys::` => `ffi::`.

This will require a semver bump of course.

rust-bindings/rust/tests/functions/mod.rs

@@ -1,6 +1,6 @@
+use crate::util::TestRepo;
 use gio::NONE_CANCELLABLE;
 use ostree::{checksum_file_from_input, ObjectType};
-use util::TestRepo;
 
 #[test]
 fn should_checksum_file_from_input() {

rust-bindings/rust/tests/repo/mod.rs

@@ -32,7 +32,7 @@ fn should_traverse_commit() {
         .expect("traverse commit");
 
     assert_eq!(
-        hashset!(
+        maplit::hashset!(
             ObjectName::new(
                 "89f84ca9854a80e85b583e46a115ba4985254437027bad34f0b113219323d3f8",
                 ObjectType::File
@@ -76,7 +76,7 @@ fn should_checkout_tree() {
         .checkout_tree(
             ostree::RepoCheckoutMode::User,
             ostree::RepoCheckoutOverwriteMode::None,
-            &gio::File::new_for_path(checkout_dir.path().join("test-checkout")),
+            &gio::File::for_path(checkout_dir.path().join("test-checkout")),
             &file,
             &info,
             NONE_CANCELLABLE,

rust-bindings/rust/tests/tests.rs

@@ -1,11 +1,3 @@
-extern crate gio;
-extern crate glib;
-extern crate openat;
-extern crate ostree;
-extern crate tempfile;
-#[macro_use]
-extern crate maplit;
-
 mod functions;
 mod repo;
 #[cfg(feature = "v2020_2")]

rust-bindings/rust/tests/util/mod.rs

@@ -30,7 +30,7 @@ impl TestRepo {
 
 pub fn create_mtree(repo: &ostree::Repo) -> ostree::MutableTree {
     let mtree = ostree::MutableTree::new();
-    let file = gio::File::new_for_path(
+    let file = gio::File::for_path(
         Path::new(env!("CARGO_MANIFEST_DIR"))
             .join("tests")
             .join("data")