Add RemovableDrive plugin that has been moved from Uranium

Since it now depends on GCodeWriter we should put it somewhere where
GCodeWriter actually exists.

plugins/RemovableDriveOutputDevice/LinuxRemovableDrivePlugin.py

@@ -0,0 +1,41 @@
+# Copyright (c) 2015 Ultimaker B.V.
+# Copyright (c) 2013 David Braam
+# Uranium is released under the terms of the AGPLv3 or higher.
+
+from . import RemovableDrivePlugin
+
+import glob
+import os
+import subprocess
+
+##  Support for removable devices on Linux.
+#
+#   TODO: This code uses the most basic interfaces for handling this.
+#         We should instead use UDisks2 to handle mount/unmount and hotplugging events.
+#
+class LinuxRemovableDrivePlugin(RemovableDrivePlugin.RemovableDrivePlugin):
+    def checkRemovableDrives(self):
+        drives = {}
+        for volume in glob.glob("/media/*"):
+            if os.path.ismount(volume):
+                drives[volume] = os.path.basename(volume)
+            elif volume == "/media/"+os.getenv("USER"):
+                for volume in glob.glob("/media/"+os.getenv("USER")+"/*"):
+                    if os.path.ismount(volume):
+                        drives[volume] = os.path.basename(volume)
+
+        for volume in glob.glob("/run/media/" + os.getenv("USER") + "/*"):
+            if os.path.ismount(volume):
+                drives[volume] = os.path.basename(volume)
+
+        return drives
+
+    def performEjectDevice(self, device):
+        p = subprocess.Popen(["umount", device.getId()], stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+        output = p.communicate()
+
+        return_code = p.wait()
+        if return_code != 0:
+            return False
+        else:
+            return True