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)
Inventory Plugin to get hostgroups from FreeIPA
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
Merge pull request #9312 from admiyo/freeipa

Inventory Plugin to get hostgroups from FreeIPA
Merge pull request #9331 from marcinpraczko/devel

Fix detecting distribution release on OpenSuSE
Added _meta hostvars key to gce.py plugin per the discussion in issue #9291.
Merge pull request #9329 from mcodd/devel

python2.4 compatibility issue with urlparse
Add --pretty option for gce inventory plugin
Add integration test for the shell module

* it ensures that it's possible to define options in the multiline block
Typo: greatful -> grateful
Add new class stubs
Move the v2 tests under the v2 tree