put Attribute into its own module, take into account prefixes when determining namespaces

src/attribute.rs

@@ -0,0 +1,24 @@
+use xml::escape::escape_str_attribute;
+
+use std::fmt;
+
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub struct Attribute {
+    pub name: String,
+    pub value: String,
+}
+
+impl fmt::Display for Attribute {
+    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
+        write!(fmt, "{}=\"{}\"", self.name, escape_str_attribute(&self.value))
+    }
+}
+
+impl Attribute {
+    pub fn new<N: Into<String>, V: Into<String>>(name: N, value: V) -> Attribute {
+        Attribute {
+            name: name.into(),
+            value: value.into(),
+        }
+    }
+}