Terminal escape sequences from configure/make test

[Hallvard B Furuseth <h.b.furuseth@usit.uio.no>]

The terminal escape sequences from 'make test >&outfile' can be a bit
annoying.  It's not hard to say 'TERM=dumb make test >&outfile', but
I forget it now and then.

I'd like to wrap the code to find terminal escape sequences in configure
and 'make test' in 'if test -t 1', which checks if file descriptor 1
goes to a terminal.

However, I'm unsure how portable 'test -t' is.  'test -t 1 2>/dev/null'
would be safe, but then only systems that support 'test -t' get escape
sequences.  Comments?

-- 
Hallvard