Regeneration and redirects for book content

Changes include:
- Change example to use FormatException instead of ExpectException.
- Don't say local vars are lazily initialized.
- Better code for the sin() example.
- Better comments (and updated code) for the hide elements example.
- Delete all dart-vm content.
- Redirect dart-vm and dart2js to /tools/*.

Staged at URLS such as:

https://book-dot-dart-lang.appspot.com/docs/dart-up-and-running/contents/ch02.html
https://book-dot-dart-lang.appspot.com/docs/dart-up-and-running/contents/ch03.html
https://book-dot-dart-lang.appspot.com/docs/dart-up-and-running/contents/ch04.html

XML diffs (probably easier to read than these, but still some randomness due to the editor changing some line lengths):

https://github.com/dart-lang/dart-up-and-running-book/pull/44

BUG= http://dartbug.com/19048 http://dartbug.com/19049 http://dartbug.com/18671 http://dartbug.com/15554 http://dartbug.com/17668
R=sethladd@google.com

Review URL: https://chromiumcodereview.appspot.com/453093005