Add tokenfromoauth1 method to upgrade to Dropbox API v2

lib/dbox.js

@@ -622,7 +622,32 @@ exports.app = function(config){
 
           var args = {
             "method": "POST",
-            "headers": { 
+            "headers": {
+              "content-type": "application/x-www-form-urlencoded",
+              "content-length": body.length
+            },
+            "url": url,
+            "body": body
+          }
+          return request(args, function(e, r, b){
+            cb(e ? null : r.statusCode, e ? null : helpers.parseJSON(b))
+          })
+        },
+
+        tokenfromoauth1: function(cb){
+          var signature = helpers.sign(options)
+          signature["root"] = root
+
+          var url = helpers.url({
+            hostname: "api.dropbox.com",
+            action: "oauth2/token_from_oauth1"
+          })
+
+          var body = qs.stringify(signature)
+
+          var args = {
+            "method": "POST",
+            "headers": {
               "content-type": "application/x-www-form-urlencoded",
               "content-length": body.length
             },

lib/helpers.js

@@ -108,12 +108,12 @@ module.exports = function(config){
         throw "must have proper base, version, and action"
 
       // calculate if fileops path
-      var fileop   = obj.action.split("/")[0] == "fileops"
+      var fileop   = obj.action.split("/")[0] == "fileops" || obj.action.split("/")[0] === "oauth2"
 
       // fileops calls desn't want root in path
       var rootpath = fileop ? "" : root
 
-      // fileops calls desn't want scope in path
+      // fileops and oauth2 calls desn't want scope in path
       var scopepath = fileop ? "" : scope
 
       // we wont always have this

test/all.js

@@ -185,6 +185,13 @@ describe("all", function(){
       done()
     })
   })
+
+  it("should get oauth2 token from oauth1 token", function(done) {
+    client.tokenfromoauth1(function(status, reply){
+      status.should.eql(200)
+      done()
+    })
+  })
 
   after(function(){
     //console.log("after step")