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


git-svn-id: svn+ssh://svn.freebsd.org/base/head@274116 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f
vt(4): Support syscons' SC_HISTORY_SIZE to configure history size

Therefore, to set histry size to 2000 lines, add the following line to
your kernel configuration file:
    options SC_HISTORY_SIZE=2000

The default history remains at 500 lines.

MFC after:	1 week


git-svn-id: svn+ssh://svn.freebsd.org/base/head@274117 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f