BUGFIX: Proxy "deadlock" corrected; sample updates.

BUGFIX: The "deadlock" problem was caused by not reading the response body from treq.
Added extra links to sample services; make SLO have a timeout and consume the responses (just in case).
PGT lifetme should not exceed the ogiginating TGT lifetime (as per the spec).
Cleaned up a few debugging log messages.
Change the default Request.redirect() behavior to be a HTTP 303.
Set up for /proxyValidate .