Make hooks work with prepared requests
Merge remote-tracking branch 'upstream/master'

Conflicts:
	requests/sessions.py
Add missing import
Refactor prepare_hooks()
Comment & replace something that keeps disappearing
Only call the hook once.
Merge branch 'master' of git://github.com/kennethreitz/requests

Conflicts:
	test_requests.py
Merge pull request #1099 from sprt/master

Make hooks work with prepared requests