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/OSXRemovableDrivePlugin.py

@@ -0,0 +1,64 @@
+# 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 threading
+
+import subprocess
+import time
+import os
+
+import plistlib
+
+## Support for removable devices on Mac OSX
+class OSXRemovableDrives(RemovableDrivePlugin.RemovableDrivePlugin):
+    def run(self):
+        drives = {}
+        p = subprocess.Popen(["system_profiler", "SPUSBDataType", "-xml"], stdout=subprocess.PIPE)
+        plist = plistlib.loads(p.communicate()[0])
+        p.wait()
+
+        for dev in self._findInTree(plist, "Mass Storage Device"):
+            if "removable_media" in dev and dev["removable_media"] == "yes" and "volumes" in dev and len(dev["volumes"]) > 0:
+                for vol in dev["volumes"]:
+                    if "mount_point" in vol:
+                        volume = vol["mount_point"]
+                        drives[volume] = os.path.basename(volume)
+
+        p = subprocess.Popen(["system_profiler", "SPCardReaderDataType", "-xml"], stdout=subprocess.PIPE)
+        plist = plistlib.loads(p.communicate()[0])
+        p.wait()
+
+        for entry in plist:
+            if "_items" in entry:
+                for item in entry["_items"]:
+                    for dev in item["_items"]:
+                        if "removable_media" in dev and dev["removable_media"] == "yes" and "volumes" in dev and len(dev["volumes"]) > 0:
+                            for vol in dev["volumes"]:
+                                if "mount_point" in vol:
+                                    volume = vol["mount_point"]
+                                    drives[volume] = os.path.basename(volume)
+
+    def performEjectDevice(self, device):
+        p = subprocess.Popen(["diskutil", "eject", path], 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
+    
+    def _findInTree(self, t, n):
+        ret = []
+        if type(t) is dict:
+            if "_name" in t and t["_name"] == n:
+                ret.append(t)
+            for k, v in t.items():
+                ret += self._findInTree(v, n)
+        if type(t) is list:
+            for v in t:
+                ret += self._findInTree(v, n)
+        return ret