Support cat -A, -E and -T, which are commonly used by Linux shell
scripts. -E prints a "$" at the end of each line, -T renders tabs
as ^I, and -A is equivalent to -vET.
MFC After: 1 week
Discussed with: jrtc27
Reviewed by: jrtc27, ziaee
Differential Revision: https://reviews.freebsd.org/D59250