Fix mount.active command on FreeBSD.

Uses `mount -p` on FreeBSD as neither of the `/proc/self` files
currently used to determine active mounts exist on FreeBSD systems.
Ensure mount options come before special and node.

Fixes calls to mount where an fstype is specified.
Update GitFS Backend Walkthrough to include GitFS over SSH

A small description on how to configure GitFS over SSH transport.
Allow slashes in gitfs envs, Fix #5007
Add docstring to interface()
Use yamlify_arg() in more places
Fix failing test for checking get_owner
Set vars to none instead of empty string
client.py: fix ye olde English typoe
Catch case where format_call stack traces and the trace is safe
module/timezone : add Solaris family support

This commit will add the support of TZ for Solaris platforms.

Tested with SmartOS
Pull #5264 : get rid of re.match as @cvrebert pointed out
Typo.
Fix #5218
Import salt.utils.winapi
Import both for completeness

Importing `salt.util.winapi` does import `salt.util` as well.  However,
having both explicitly shows that both are being used, and matches the
pattern we use elsewhere.  Additionally, as far as I know it doesn't
have any real performance costs, as it doesn't reimport `salt.utils` if
it's already loaded.
Fix for #4920, needs to confirm
Add vars reference document. Fix #5220
modules/virt.py: use qemu-img to detect image type; allow emulator type (e.g., kvm, qemu) to be passed as an arg to init
Only load module if windows required imports are available.

Seems the way to do it and also stops an import traceback to be logged on Linux when importing `salt.utils.winapi`.