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.
Ensure mount options in remount come before special + node.

Fixes calls to mount where an fstype is specified.
added "--ask n" to eix-sync (see #5148)
added functions for FEATURES variable
Resolve bug where states/cmd.py _run_check() function was mutating cmd_kwargs (using pop function) which caused subsequent cmd's to runas/user = None (default user) instead of specified user.

unless and onlyif break runas user cmd.[run, script, call]

We will supply a patch to resolve
	modified:   cmd.py
Cleaned up _run_checks()'s docstring and return dictionaries comments

	modified:   cmd.py
modules/zpool : add iostat function

Displays I/O statistics for the given pools
bridge mod: add spaces after commas

************* Module salt.modules.bridge
C0324:211,4:_os_dispatch: Comma not followed by a space
Merge pull request #5228 from cvrebert/patch-4

bridge mod: add spaces after commas
fix new pylint W1401 (Anomalous backslash in string) instances
Various pylint fixes to the xapi module

************* Module salt.modules.xapi
E0602: 58,14:_get_xapi_session: Undefined variable 'CommandExecutionError'
W0702: [many instances]: No exception type(s) specified
zfs module: rm unused import of the `os` std lib module
bridge module: avoid bare `except:`

************* Module salt.modules.bridge
W0702:287,12:find_interfaces: No exception type(s) specified
pkg state: fix pylint W0604

************* Module salt.states.pkg
W0604: 48,4: Using the global statement at the module level
modules/zpool : add scrub function

Begin a scrub on selected zpool
Merge pull request #5238 from virtua-network/zpool_module

Zpool module
Merge pull request #5232 from cvrebert/patch-5

zfs module: rm unused import of the `os` std lib module
Merge pull request #5230 from hulu/xapi

Various pylint fixes to the xapi module
Merge pull request #5233 from cvrebert/patch-6

bridge module: avoid bare `except:`