Use file.separator in pom path relativization.

Fixes #944 I think.

bin/lein

@@ -189,6 +189,7 @@ export JVM_OPTS="${JVM_OPTS:-"$JAVA_OPTS"}"
 # you need to remove the self-install and upgrade functionality or see lein-pkg.
 if [ "$1" = "self-install" ]; then
     if [ -r "$BIN_DIR/../src/leiningen/version.clj" ]; then
+        echo "Running self-install from a checkout is not supported."
         echo "See CONTRIBUTING.md for SNAPSHOT-specific build instructions."
         exit 1
     elif [ -r "$LEIN_JAR" ]; then

src/leiningen/pom.clj

@@ -7,7 +7,7 @@
             [clojure.data.xml :as xml]))
 
 (defn- relativize [project]
-  (let [root (str (:root project) "/")]
+  (let [root (str (:root project) (System/getProperty "file.separator"))]
     (reduce #(update-in %1 [%2]
                         (fn [xs]
                           (if (seq? xs)