Moved all inclusion code to prepend.php, because script may die or other wise exit before this gets included/executed.

applied changes from PR https://github.com/gajus/xhprof.io/pull/39.
kudos to @thebeline.
Merge pull request #7 from staabm/allinprepand2

Moved all inclusion code to prepend.php, because script may die or other...