Remove $FreeBSD$: one-line .c pattern

Remove /^[\s*]*__FBSDID\("\$FreeBSD\$"\);?\s*\n/

Fix bad error messages from dpv(3)

Before = dpv: <__func__>: posix_spawnp(3): No such file or directory
After = dpv: <path/cmd>: No such file or directory

Most notably, show the 2nd argument being passed to posix_spawnp(3)
so we know what path/cmd failed.

Also, we don't need to have "posix_spawnp(3)" in the error message
nor the function because that can [a] change and [b] traversed using
a debugger if necessary.

Add new libraries/utilities for data throughput visualization.
dpv(3): dialog progress view library
dpv(1): stream data from stdin or multiple paths with dialog progress view
figpar(3): configuration file parsing library

Reviews: D714
Reviewed by: jelischer, shurd
Discussed at: MeetBSD California 2014 Vendor/Dev Summit
Discussed on: -current
MFC after: 21 days
X-MFC-to: stable/10 stable/9