Add zoom to extent control

I create an example page named navigation-controls to have a common example for  'Zoom to extent', 'Zoom to position' and 'Pan buttons'.

I try `./build.py check` and `./build.py integration-test`, but I have an exception:
```
Traceback (most recent call last):
  File "./build.py", line 759, in <module>
    main()
  File "/home/sbrunner/workspace/ol3/pake.py", line 339, in main
    target.build(dry_run=options.dry_run)
  File "/home/sbrunner/workspace/ol3/pake.py", line 92, in build
    timestamp = max(timestamp, target.build(dry_run=dry_run))
  File "/home/sbrunner/workspace/ol3/pake.py", line 92, in build
    timestamp = max(timestamp, target.build(dry_run=dry_run))
  File "/home/sbrunner/workspace/ol3/pake.py", line 107, in build
    self.action(self)
  File "./build.py", line 358, in build_lint_src_timestamp
    t.newer(t.dependencies))
  File "/home/sbrunner/workspace/ol3/pake.py", line 207, in run
    subprocess.check_call(args, **kwargs)
  File "/usr/lib/python2.7/subprocess.py", line 506, in check_call
    retcode = call(*popenargs, **kwargs)
  File "/usr/lib/python2.7/subprocess.py", line 493, in call
    return Popen(*popenargs, **kwargs).wait()
  File "/usr/lib/python2.7/subprocess.py", line 679, in __init__
    errread, errwrite)
  File "/usr/lib/python2.7/subprocess.py", line 1249, in _execute_child
    raise child_exception
OSError: [Errno 2] No such file or directory
```

But I have the same exception on master...