Allow priority setting from torrent context menu

client/source/scripts/constants/PriorityLevels.js

@@ -0,0 +1,15 @@
+const PriorityLevels = {
+  file: {
+    0: 'Don\'t Download',
+    1: 'Normal',
+    2: 'High'
+  },
+  torrent: {
+    0: 'Don\'t Download',
+    1: 'Low',
+    2: 'Normal',
+    3: 'High'
+  }
+};
+
+export default PriorityLevels;