Remove old updates on startup.

We left the packages from old Updates lingering on the filesystem. This
clears them out.

Fixes #28

src/system/UpdateManager.cpp

@@ -54,6 +54,8 @@ QString UpdateManager::HaveUpdate()
   {
     // check if this version has been applied
     QString readyFile(GetPath("_readyToApply", dir, false));
+    QString packagesDir(GetPath("packages", dir, false));
+
     QLOG_DEBUG() << "Checking for:" << readyFile;
 
     QDir packageDir(GetPath("packages", dir, false));