Don't use qDebug and qWarning for formatted output

They are not meant to be used like that. If you want formatted output to
the console, use stdio.h functions or std::cout. Otherwise, you get
something like:

 $ qmlscene -h
 [233103.196] (126848)(usage|?qmlscene?|__libc_start_main|?qmlscene?): Usage: qmlscene [options] <filename>
 [233103.197] (126848)(usage|?qmlscene?|__libc_start_main|?qmlscene?):
 [233103.197] (126848)(usage|?qmlscene?|__libc_start_main|?qmlscene?):  Options:
 [233103.198] (126848)(usage|?qmlscene?|__libc_start_main|?qmlscene?):   --maximized ............................... Run maximized
 [...]

I've replaced all qDebug with puts/printf and most qWarning with fprintf
to stderr. In my opinion, some of the qWarnings aren't errors, so I
replaced those with puts/printf too.

Change-Id: I3e493950bc4a588059fec6c7441b010c2780dffd
Reviewed-by: Simon Hausmann <simon.hausmann@digia.com>