nsh is a work in progress, diffs are welcome

Cleanup:

* Document all new commands in the manual
* Some formatting for the manual.  Simple markdown format?
* Bug hunt

To be implemented: 

* handle newer bridge commands
* handle newer 802.11 gunk like rssi display, chan, flags
* ndp controls
* handle kernel sppp/pppoe client
* privsep? multiple daemons? web front end using privsep?
* Build a simple web interface that works through the rc file handler or
  via imsg
* copy configs from/to tftp/ftp/http/other parts of filesystem/etc
* RSA certificate generation/management method (isakmpd, iked, sshd)
* Persistent comments/remarks in the config file (to document routes, etc..)
  (this was already done for rtable descriptions, and the database could be
  used the same way for routes)
* Better support for paging through displays of text X lines at a time
* Something comparable to pipe-grep for matching output
* Context-sensitive help
* Generate example configs for BGP+MPLS, IPv6+BGP, IPv6+Link local GIF,
  vether+bridge, and many other interesting feature combinations/scenarios.

Would be nice:

* Perhaps some way for the shell to upgrade itself, or the entire system/
  flash image when given a network source for new binaries?
  (requires our environment be known, this may be doable with flashrd,
  doable in a different way with a typical install, etc)
* Add more diagnostic messages for verbose output where useful
* Convenient/automatic mechanisms to centralize configurations for
  tracking/revision control
  (can already be done by adding cvs/git/... calls to save.sh)

Known Bugs (or, things that I don't want to bother with right now, but
better not forget later...):

* The kernel does not keep count of information displayed in 'show rtstat'
  properly (what else??)
  (Very old, possibly no longer valid)
* The kernel/wireless drivers do not use txpower data in any way.  Also
  TXPOWER_AUTO does absolutely nothing and is not even tracked in the kernel.
  (Very old, possibly no longer valid)
