dirfs - Fix a panic on shutdown.

* Do not attempt to release root inode if there was no call
  to VFS_ROOT()
dirfs - Lower debug level to 0
nvi: Upgrade from version 1.79 to 2.1.1 (multibyte support)

The DragonFly NVI ("new" vi and ex) has been at version 1.79 which,
according to the FreeBSD repository, was imported nearly 18 years
ago in October 1996.

A 2011 Summer of Code project of FreeBSD added multibyte encoding
support with iconv.  With the recent update to the base iconv
support, DragonFly users can enjoy multibyte support. Language
catalogs are still based on English, French, German, Dutch,
Spanish, Chinese, Russian, Polish, and Swedish.  FreeBSD brought
this NVI update into their HEAD in August 2013.  Local
modifications to nvi 1.79 were incorporated directly on top of
this sync.

Repository: <https://github.com/lichray/nvi2>