New version of jng (2.0)

[dteske]

Summary

Changes for jng 1.0 -> 2.0 include:

+ Add experimental MSS clamping
+ Add support for ng_bridge(4) NGM_BRIDGE_GET_STATS (getstats)
+ Add JSON formatted ng_bridge(4) statistics (see above) via "jng stats -j <name>"
+ Add error messages
+ Minor refactoring for code readability (read: quietly() function)
+ Rename eiface variables to jiface to clarify as-for jail interface (not ng_eiface(4))
+ Fix missing description for alternate form of "jng show" usage
+ Update "jng show <name>" to accept multiple names (now "jng show <name> …" is allowed)
+ Update "jng shutdown <name>" to accept multiple names (now "jng shutdown <name> …" is allowed)
+ Add "-a" option to "jng stats" (as-in "jng stats -a") to show all ng_bridge(4) stats
+ Update "jng stats <name>" to accept any kind of name (make it easier to use)
+ Add version ident
+ Remove extraneous line in LICENSE section
+ Add -h to usage statements
+ Bump copyright

Test Plan

Drop-in replacement for jng-1.0

[dteske]

Update

[dteske]

Bump copyright

[dteske]

Advertise -j option in stats usage statement

[dteske]

Fix variable name in awk -- s/time/tm/

[jlduran_gmail.com]

Nice!
I have slightly tested it, and it is backwards compatible... even with the old (unrelated) bug 268397 (this is probably a race somewhere else), that reproduces easily by stopping/starting the jail service 10 times (repo/branch here: https://github.com/jlduran/jng-jib-jails-test/tree/jng2)