Fix explanation of when focusing is allowed

Nitpick, but triggering programmatic events calls event handlers
synchronously, and can focus things fine, the problem demonstrated in
this example page is that (in Safari on iOS < 5) touchend event handlers
just can't focus things. Here's a page with more discriminatory test
cases:
http://jsbin.com/gixaduni/2
Fix typo in example test page: s/instread/instead/

https://github.com/ftlabs/fastclick/pull/233#issuecomment-38866675
Merge pull request #233 from laughinghan/patch-1

Fix explanation of when focusing is allowed