Various updater fixes

Updater tests for path utils
The updater now doesn't use splitpath on Windows (fixes problems with Windows XP)
Fix up paths for the OSX updater - should now install the updates into the right place
Fix translations install path - translation isntall and deploy should be fixed

logic/updater/DownloadUpdateTask.h

@@ -198,7 +198,21 @@ protected:
 	 * Filters paths
 	 * Path of the format $PWD/path, it is converted to a file:///$PWD/ URL
 	 */
-	static QString preparePath(const QString &path);
+	static QString fixPathForTests(const QString &path);
+
+	/*!
+	 * Filters paths
+	 * This fixes destination paths for OSX.
+	 * The updater runs in MultiMC.app/Contents/MacOs by default
+	 * The destination paths are such as this: MultiMC.app/blah/blah
+	 * 
+	 * Therefore we chop off the 'MultiMC.app' prefix and prepend ../..
+	 * 
+	 * Returns false if the path couldn't be fixed (is invalid)
+	 * 
+	 * Has no effect on systems that aren't OSX
+	 */
+	static bool fixPathForOSX(QString &path);
 
 protected slots:
 	void vinfoDownloadFinished();