add bcm7241 support

Signed-off-by: Mike Looijmans <milo-software@users.sourceforge.net>
Print messages to stderr instead of stdout

Output all that debug talk to stderr. This frees up stdout so you can
grab to a stream instead, which might be very useful.

Remove a few old debug lines. And don't mention the version number,
it has been 1.0 since the dawn of ages, so no one seems to care.
Support stdout as image destination

Allows grabbing screenshots over SSH and similar remote links.
Also remove the filename limitation, can exceed 255 characters now.
Merge branch 'master' of git://git.code.sf.net/p/openpli/aio-grab