A working IPSEC implementation (1/many)

* Fix fast_ipsec(4) so that it at least builds.
* Untested and probably not working.

Reported-by: Thomas Nikolajsen
Dragonfly-bug: <http://bugs.dragonflybsd.org/issues/1843>
declare functions local to df module as static

This makes it compliant to style(9).
df -hi prints inodes count "human-readable"

Enable "human-readable" printing of inodes count when df(1)
is called with both -h and -i flags. This is similar to what can be
found on FreeBSD df(1) or GNU df(1).

The code has been adapted from FreeBSD's df(1) and the manpage updated
accordingly.

Example output:

Now:
% df -hi
Filesystem                           Size   Used  Avail Capacity iused ifree %iused  Mounted on
[...]
/dev/serno/VB6cbedbd6-0a1f16ee.s1a   756M   302M   393M    43%     949   96k    1%   /boot
[...]

Before:
% df -hi
Filesystem                           Size   Used  Avail Capacity iused ifree %iused  Mounted on
[...]
/dev/serno/VB6cbedbd6-0a1f16ee.s1a   756M   302M   393M    43%     949 96329    1%   /boot
[...]
Add -T option to df(1).

Add -T option to df(1) as found in Linux and FreeBSD df(1).
When given, file system type will be included in df(1) output.
This has been adapted from FreeBSD df(1).
Fix memory leak in df(1)

Fix a memory leak in makenetvfslist which would occur when a previous
call to strdup fails and the function returns on error.
The simple fix is a call to free(3) to free memory allocated to listptr
before returning.