MFC: r282305, r282309, r282342, r282669, r282722

MFC: r282305, r282309, r282342, r282669, r282722

r282305:
col: fixing 25 year old bug

Makes col(1) respect POSIX again for escape sequences as decribed in its manpage
The bug was introduced in CSRG in 1990

r282309:
Use defines to improve clarity

r282342:
Capsicumize col(1)

r282669:
Fix about ten integer overflows and underflows and a handful of logic
errors in line number handling.

Submitted by:	schwarze at OpenBSD
Discussed with:	schwarze at OpenBSD
Obtained from:	OpenBSD

r282722:
For half and reverse line feeds, recognize both SUSv2-style escape-digit
and BSD-style escape-control-char sequences in the input stream.

Submitted by:	schwarze at OpenBSD
Discussed with:	schwarze at OpenBSD
Obtained from:	OpenBSD

git-svn-id: svn://svn.freebsd.org/base/stable/10@282949 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f