Allow jail sysctl's to be empty
Missing MiddlewareError import causing traceback

Ticket:	#4128
Extend zfs_get_options middleware method

Allow it to be recursive, accept no dataset argument and a list of
properties to retrieve.

Ticket:	#4125
Add compression column to the volumes datagrid

Ticket:	#4125
Add compression ratio to the volumes datagrid

Ticket:	#4125
Fix undefined name in zfs destroy error branch

While I'm here fix some PEP8 stylish things.
Do not show "Drag" tooltip if the form is hidden

Ticket:	#4119
Document snapshot API

Ticket:	#4059
Turn off mDNSResponder in netatalk - it's buggy and causes crashes.  Trying
a work-around registration technique for now.
Ticket: #4113
Merge branch 'master' of gitserver.ixsystems.com:/git/repos/freenas-build/freenas
The netatalk mDNS registrtion code is buggy.

Use an external registration to avoid netatalk bugs.
Disable zeroconf properly for netatalk (helps when you read the port first!)
CARP interfaces are exempt of network overlap constraint
Allow -'s and .'s in the netbios name

Ticket: #4133
Netmask should be readonly for CARP
New version of the logo.

Ticket: #4142
Enforce the 32 bits netmask for CARP in the form as well
Remove a redundant makefile build phase.
Add missing pipes import

Ticket:	#4143
Add a rebuild target for convenience.