Removed special directory listing for NFSv4. fate#315589
Do not encourage fsid=0 usage in case of NFSv4 exports. fate#315589
Removed notes of fsid=0 and bind= from help. fate#315589
Updated changelog
Removed old fashioned testsuite.

It was already disabled and we migrate to rspec. RIP.
Updated testsuite.
UI: removed firewall widget's outter frame

Custom widget provided by firewall module contains frame already.
Refactoring: querying current export dir moved into own function
Merge pull request #14 from mchf/master

Dropped special handling for NFSv4 exports. Fate#315589