Clean up Track Widget.

- adjust margins
- display speed or pace
- display total time or total moving time
- use km intead of m when distance is greater than 1 km
- use mi instead ft when distance is greater than 1 mi

MyTracks/res/values/dimens.xml

@@ -0,0 +1,19 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+Copyright 2012 Google Inc.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+     http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+-->
+<resources>
+  <dimen name="widget_margin">8dp</dimen>
+</resources>