Add a parent_domain option for auth_tkt policy

This change adds a new ``parent_domain`` option to
``AuthTktAuthenticationPolicy`` which sets the authentication cookie as
a wildcard cookie on the parent domain. This
is useful if you have multiple sites sharing the same domain.
Merge branch 'master' of github.com:Pylons/pyramid
Merge branch 'master' of github.com:Pylons/pyramid
Merge branch 'auth-parent-domain' of github.com:wichert/pyramid into wichert-auth-parent-domain
Merge branch 'wichert-auth-parent-domain'
normalize notations used for string and json renderer return values, closes #1005
version bump in setup.py conf.py CHANGES.txt, rejigger changes bugs vs. features
add whatsnew-1.5
Fix documentation of testing.setUp
Merge pull request #1051 from ronnix/patch-5

Fix documentation of testing.setUp
Merge pull request #1048 from stevepiercy/master

Synch some differences between index.rst and latexindex.rst, with index.rst as master
Remove references to relocated PyCharm tutorial