moc: add unittest for --ignore-option-clashes

Based on tst_Moc::frameworkSearchPath().

Change-Id: I4f44f98d62acc1a2a92739cceba731dcb5f661b6
Reviewed-by: Olivier Goffart <ogoffart@woboq.com>
Fixed QTextStream "stdin" auto tests

On some platforms (like BlackBerry) qDebug doesn't write to stderr,
so we directly write to stderr with fprintf.

Change-Id: Ib86211c98cf4da1fa2dbea4600a78e2013dc1a5a
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>