Add autoreject_file support to minion authentication

This commit adds support for a file similar to autosign_file, which can
be used to automatically reject minions which match the expressions
inside it.
prepend root_dir to autoreject_file
Add autoreject_file to master config template
Add autoreject_file to master config file documentation

Included a versionadded directive to note when this was added, to reduce
confusion.
First attempt at abstracting ZeroMQ communication.
Complete abstraction of ZeroMQ.
Updated the index of the troubleshooting docs with some new links to master and minion docs, added those, did not add content yet.
Don't assume that grep-available is available
dockerio module: docs syntax and formatting
Refactor yumpkg5 arch handling

When I originally wrote the mutli-arch support in this module, it was
done hastily and was not well-designed. For instance, it assumes that
x86_64 is the only arch for which packages from other arches are
supported. It additionally doesn't support ARM architectures at all,
making it completely useless on those devices.

This commit handles architectures in a more elegant way. Salt will now
only refer to the package with the arch appended if the arch both A) is
not 'noarch', and B) does not match the 'osarch' grain. This cleans
up the logic significantly, as well as enabling proper support for ARM
devices (though this is still untested).
Fixes pillar namespace merging not preserving order when replacing keys
Remove trailing semicolons from previous commit
Unit testing of ps exec module.

Seemed like this would be sort of mundane but there are actually a few dragons here.
Unit testing turned up the fact that we make use of methods in psutil that are deprecated!
Lint.
Compensate for time spent waiting for events
Merge pull request #9303 from cachedout/ps-unit-tests

Ps unit tests
Merge pull request #9298 from terminalmage/refactor-yumpkg-multiarch

Refactor yumpkg5 arch handling
Fix issue #7157
`exsel` matching is no longer supported.
Restore event subscription