Adding execution and state modules for xmpp
We don't need to pull the roster
Merge pull request #9422 from techhat/xmpp

Adding execution and state modules for xmpp
White-space related lint fixes.
Include the coding header
PyLint wrongly reports an error about calling `super()`
Merge pull request #9423 from cachedout/pkg-doc-fix

Add note about refresh option to pkg state.
Disabled the wrong Pylint code
Add a fake class to avoid problems when `sleekxmpp` is not available.
Merge pull request #9427 from s0undt3ch/develop

Add a fake class to avoid problems when `sleekxmpp` is not available
clean up in the pkg state.
Added date to release notes for recent salt versions

These dates were pulled out of the Git commit for the tag (with a Vim
macro). I didn't go back before we started tagging releases with
annotated tags since that would take some mailing list archaeology. Also
there might be a couple instances where the tag came plus or minus a day
or two from the announcement.

Closes #9426
Updated the master troubleshooting docs with an example of modifying the limits.conf.
Merge pull request #9428 from gravyboat/develop

Update to pkg state example, and master troubleshooting topic.
Added a line explaining that the user would need to re-establish their sessions as the user they modified the limits for in the master troubleshooting guide.
Add new XMPP module/state to docs
Add versionadded directive to XMPP module/state

Also cleaned up the RST formatting a bit
Merge pull request #9429 from gravyboat/develop

Master troubleshooting guide update regarding ulimit refresh.
Merge pull request #9430 from terminalmage/docs

Add new XMPP module/state to docs
Fix docs for the "Understanding State Ordering" tutorial

"code-block" directives require a blank line before them.