Enable the usage of existing 'salt-call -m' option.

Currently, the ``-m`` flag for salt-call has no effect in the loaders.
This commit allows users to specify exactly the module dirs to load
given that they follow the naming conventions for 'grains', 'runners',
'modules', 'states', etc. This is a shortcut for having to refresh cache
state when using a masterless salt-call.
allow matching on presence of a key when value is a dict
allow matching on presence of a key when value is a dict -- for grains too
Adding startup scripts for salt-bootstrap to use on OpenBSD
Perform a 'systemctl --system daemon-reload' when needed

If a custom unit file is added to /etc/systemd/system, or the given unit
has been modified since the last time systemctl --system daemon-reload
was run, perform the daemon-reload.
Look for custom initscripts in /etc/init.d

While RHEL symlinks /etc/init.d to /etc/rc.d/init.d, /etc/init.d is the
path typically referenced, and indeed /sbin/service looks directly in
/etc/init.d. This commit will account for the corner-case where a distro
does not symlink /etc/init.d to /etc/rc.d/init.d/.
Merge pull request #4228 from kmwhite/feature-add_openbsd_startup_scripts

Adding startup scripts for salt-bootstrap to use on OpenBSD
Add some more debugging logging. Remove double quotes.
Fix log message. The file might not have been loaded(if it does not exist for example).
Merge pull request #4233 from s0undt3ch/develop

Add some more debugging logging. Remove double quotes.
Merge pull request #4230 from terminalmage/develop

Look for custom initscripts in /etc/init.d
fix typo
Merge pull request #4234 from giantlock/develop

fix typo
Added notes on installing psutil via pip

Python header files are required, and may not be installed depending on
your distro. Added a paragraph mentioning this.
Merge pull request #4235 from terminalmage/docs

Added notes on installing psutil via pip
Use helper function to build unit name

_canonical_unit_name() already appends '.service' to a non-canonical
unit name, no need to duplicate efforts here.
Remove ReST syntax from salt.utils.is_true

This function won't have its docstring parsed to be displayed in the
docs, so it doesn't need fancypants ReST directives.
Add salt.utils.test_mode

This is the first step in making "test" mode for states
case-insensitive. See #3363.
Slight docstring tweak
correct description