Update playbooks_roles.rst

Fixes https://github.com/ansible/ansible/issues/7241
Removing hard coded link and replacing with reference
Remove no-op string declaration
Use https for git submodules

It's much more likely that people can use the https protocol
than the git protocol (many firewalls block the latter)
Update the core and extras submodules
Fixing item loop when undefined variable errors occur because of missing attributes

Fixes a case where the variable 'foo' may exist, but the with_items loop
was used on something like 'foo.results', where 'results' was not a valid
attribute of 'foo'. Prior to this patch, conditionals were not evaluated
until later, meaning there was no opportunity to allow a test to skip the
task or item based on it being undefined.
Fixing bad variable naming choices
add missing headers, rm the subtree of ansible/inventory as we wish to overhaul it.
Inventory Plugin to get hostgroups from FreeIPA
Start converting asserts to self.assert*() so we get better error messages
Update other asserts that have a py2.6 unittest method
Python3 fix
Python3 fix
Python3 test target and use coverage for all v2 tests.
python2.4 compatibility issue with urlparse
Typo: recieve -> receive.
Fix detecting distribution release on OpenSuSE

Ansible raised exception during parsering /etc/SuSE-release file.
Regular expresion should use string instead of list.
Fix tested on OpenSuse 13.1
Merge pull request #9328 from Batmat/fix-receive-typo

Typo: recieve -> receive.
Merge pull request #9299 from weargoggles/quoted-comment

Remove no-op string declaration
Merge pull request #9303 from willthames/gitmodules_over_https

Use https for git submodules