Add logfile support

Usage: flashrom --output logfile.txt

Logfile output has at least dbg2 verbosity or screen verbosity,
whichever is greater.

Corresponding to flashrom svn r1540.

Signed-off-by: Carl-Daniel Hailfinger <c-d.hailfinger.devel.2006@gmx.net>
Tested on Linux, Windows and FreeBSD.
Acked-by: Idwer Vollering <vidwer@gmail.com>
4 files changed