Remove the -rs suffix of jid, minidom and xmpp

We know those are Rust libraries, no need to add it to the path.  This
synchronises their directory with the crate name, hopefully reducing
confusion.

minidom/src/namespaces.rs

@@ -0,0 +1,38 @@
+// Copyright (c) 2020 Emmanuel Gil Peyrot <linkmauve@linkmauve.fr>
+// Copyright (c) 2020 Astro <astro@spaceboyz.net>
+// Copyright (c) 2020 Maxime “pep” Buquet <pep@bouah.net>
+// Copyright (c) 2020 Xidorn Quan <me@upsuper.org>
+//
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+#[derive(Clone, Copy, PartialEq, Eq, Debug)]
+/// Use to compare namespaces
+pub enum NSChoice<'a> {
+    /// The element must have no namespace
+    None,
+    /// The element's namespace must match the specified namespace
+    OneOf(&'a str),
+    /// The element's namespace must be in the specified vector
+    AnyOf(&'a [&'a str]),
+    /// The element can have any namespace, or no namespace
+    Any,
+}
+
+impl<'a> From<&'a str> for NSChoice<'a> {
+    fn from(ns: &'a str) -> NSChoice<'a> {
+        NSChoice::OneOf(ns)
+    }
+}
+
+impl<'a> NSChoice<'a> {
+    pub(crate) fn compare(&self, ns: &str) -> bool {
+        match (ns, &self) {
+            (_, NSChoice::None) => false,
+            (_, NSChoice::Any) => true,
+            (ns, NSChoice::OneOf(wanted_ns)) => &ns == wanted_ns,
+            (ns, NSChoice::AnyOf(wanted_nss)) => wanted_nss.iter().any(|w| &ns == w),
+        }
+    }
+}