network/nfs01: add IPv6 test-cases

* cleanup test, apply test_net.sh library
* don't use loop for test binaries because there is only one
  right now, 'open_files'
* use tst_tmpdir()
* update test-cases in runtest, add NFS over IPv6
* make four test-cases with NFS v3 and v4.

Signed-off-by: Alexey Kodanev <alexey.kodanev@oracle.com>
Acked-by: Cyril Hrubis <chrubis@suse.cz>
3 files changed