Mode improvements for UI (#3109)

* `--mode=off` now works.

* Add Mode::Off as a persistent CLI option.

* "last" not "auto" as default.

* Commit accidentally unsaved file.

* Whitespace

[ci:skip]

* Mode CLI parse fix

* or offline

* Save mode when it gets changed.

* Fix Offline mode

* Fix up mode operations.

* Make passive default, but not overriding.

* Fix test

* Maybe not everyone wants to run an archive node...

js/src/jsonrpc/interfaces/ethcore.js

@@ -166,7 +166,7 @@ export default {
   },
 
   mode: {
-    desc: 'Get the mode. Results one of: "active", "passive", "dark", "off".',
+    desc: 'Get the mode. Results one of: "active", "passive", "dark", "offline".',
     params: [],
     returns: {
       type: String,
@@ -330,7 +330,7 @@ export default {
     params: [
       {
         type: String,
-        desc: 'The mode to set, one of "active", "passive", "dark", "off"'
+        desc: 'The mode to set, one of "active", "passive", "dark", "offline"'
       }
     ],
     returns: {

js/src/views/Status/data/rpc.json

@@ -926,6 +926,16 @@
       ],
       "outputFormatter": null
     },
+    {
+      "name": "ethcore_setMode",
+      "desc": "Changes current operating mode",
+      "params": [
+        "`DATA`- Mode name"
+      ],
+      "returns": "`Boolean` - whether the call was successful",
+      "inputFormatters": null,
+      "outputFormatter": null
+    },
     {
       "name": "ethcore_setMinGasPrice",
       "desc": "Changes minimal gas price for transaction to be accepted to the queue.",
@@ -1030,6 +1040,14 @@
       "inputFormatters": [],
       "outputFormatter": null
     },
+    {
+      "name": "ethcore_mode",
+      "desc": "Returns current mode",
+      "params": [],
+      "returns": "`DATA` - Mode",
+      "inputFormatters": [],
+      "outputFormatter": null
+    },
     {
       "name": "trace_filter",
       "desc": "Returns traces matching given filter",