Add javascript OAuth support

app/assets/javascripts/oauth.js

@@ -0,0 +1,32 @@
+//= require sha
+//= require ohauth
+
+$(document).ready(function () {
+  $.ajaxPrefilter(function(options, jqxhr) {
+    if (options.oauth) {
+      var ohauth = window.ohauth;
+      var url = options.url.replace(/\?$/, "");
+      var params = {
+        oauth_consumer_key: OSM.oauth_consumer_key,
+        oauth_token: OSM.oauth_token,
+        oauth_signature_method: "HMAC-SHA1",
+        oauth_timestamp: ohauth.timestamp(),
+        oauth_nonce: ohauth.nonce()
+      };
+
+      for (var name in jqxhr.data) {
+        params[name] = jqxhr.data[name];
+      }
+
+      params.oauth_signature = ohauth.signature(
+        OSM.oauth_consumer_secret,
+        OSM.oauth_token_secret,
+        ohauth.baseString(options.type, url, params)
+      );
+
+      options.headers = {
+        Authorization: "OAuth " + ohauth.authHeader(params)
+      };
+    }
+  });
+});