doc: add 'Get Started with Go' video, remove some older videos

(I also updated the wiki's GoTalks page with all the latest videos.)

R=golang-dev, r
CC=golang-dev
https://golang.org/cl/6441113

doc/docs.html

@@ -139,6 +139,13 @@ before Go 1 and contain some examples that are no longer correct, but they are
 still of value.
 </p>
 
+<h3 id="video_tour_of_go"><a href="http://research.swtch.com/gotour">A Video Tour of Go</a></h3>
+<p>
+Three things that make Go fast, fun, and productive:
+interfaces, reflection, and concurrency. Builds a toy web crawler to
+demonstrate these.
+</p>
+
 <h3 id="go_concurrency_patterns"><a href="http://www.youtube.com/watch?v=f6kdp27TYZs">Go Concurrency Patterns</a></h3>
 <p>
 Concurrency is the key to designing high performance network services. Go's concurrency primitives (goroutines and channels) provide a simple and efficient means of expressing concurrent execution. In this talk we see how tricky concurrency problems can be solved gracefully with simple Go code.
@@ -157,21 +164,6 @@ and unveils the <a href="http://blog.golang.org/2011/05/go-and-google-app-engine
 See the <a href="/doc/talks/io2011/Writing_Web_Apps_in_Go.pdf">presentation slides</a>.
 </p>
 
-<h3 id="real_world_go"><a href="http://www.youtube.com/watch?v=7QDVRowyUQA">Real World Go</a><font color="red">*</font></h3>
-<p>
-A talk by Andrew Gerrand presented at Google I/O Bootcamp 2011.
-It gives a broad overview of Go's type system and concurrency model
-and provides four examples of Go programs that solve real problems.
-See the <a href="/doc/talks/io2011/Real_World_Go.pdf">presentation slides</a>.
-</p>
-
-<h3 id="integrated_apps"><a href="http://www.youtube.com/watch?v=Mo1YKpIF1PQ">Building Integrated Apps on Google's Cloud Platform</a></h3>
-<p>
-A talk by Andrew Gerrand presented at Google Developer Day Japan 2011.
-It discusses the development of a web application that runs on Google
-App Engine and renders images that it stores on Google Cloud Storage.
-</p>
-
 <h3 id="go_programming"><a href="http://www.youtube.com/watch?v=jgVhBThJdXc">Go Programming</a><font color="red">*</font></h3>
 <p>
 A presentation delivered by Rob Pike and Russ Cox at Google I/O 2010.  It
@@ -180,14 +172,6 @@ examples demonstrating features particular to Go.  These include concurrency,
 embedded types, methods on any type, and program construction using interfaces.
 </p>
 
-<h3 id="practical_go_programming"><a href="http://www.youtube.com/watch?v=2-pPAvqyluI">Practical Go Programming</a><font color="red">*</font></h3>
-<p>
-This talk presents the development of a complete web application in Go.
-It looks at design, storage, concurrency, and scaling issues in detail, using
-the simple example of an URL shortening service.
-See the <a href="http://wh3rd.net/practical-go/">presentation slides</a>.
-</p>
-
 <h4 id="talks_more">More</h4>
 <p>
 See the <a href="http://code.google.com/p/go-wiki/wiki/GoTalks">GoTalks