Auto merge of #14592 - asajeffrey:util-goodbye, r=mbrubeck

Remove the util crate

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This PR removes the `util` crate.

* Replaced the `spawn_named` and `clamp` functions by appropriate uses of `std:🧵:Builder::spawn`, `std::cmp::min` and `std::cmp::max`.
* Moved `opts`, `prefs` and `resource_files` into a new `config` crate.
* Moved `remutex` and `geometry` into their own crates.

---
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- [X] `./mach build -d` does not report any errors
- [X] `./mach test-tidy` does not report any errors
- [X] These changes do not require tests because they are refactorings

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components/bluetooth/lib.rs

@@ -10,7 +10,6 @@ extern crate ipc_channel;
 extern crate rand;
 #[cfg(target_os = "linux")]
 extern crate tinyfiledialogs;
-extern crate util;
 extern crate uuid;
 
 pub mod test;
@@ -29,7 +28,6 @@ use std::collections::{HashMap, HashSet};
 use std::string::String;
 use std::thread;
 use std::time::Duration;
-use util::thread::spawn_named;
 
 // A transaction not completed within 30 seconds shall time out. Such a transaction shall be considered to have failed.
 // https://www.bluetooth.org/DocMan/handlers/DownloadDoc.ashx?doc_id=286439 (Vol. 3, page 480)
@@ -88,9 +86,9 @@ impl BluetoothThreadFactory for IpcSender<BluetoothRequest> {
     fn new() -> IpcSender<BluetoothRequest> {
         let (sender, receiver) = ipc::channel().unwrap();
         let adapter = BluetoothAdapter::init().ok();
-        spawn_named("BluetoothThread".to_owned(), move || {
+        thread::Builder::new().name("BluetoothThread".to_owned()).spawn(move || {
             BluetoothManager::new(receiver, adapter).start();
-        });
+        }).expect("Thread spawning failed");
         sender
     }
 }