QImage creations fails causing QPainter to fail

Need to check for QImage failure otherwise it will through a qWarning.
Change from qWarning to qDebug

This way we can test with QT_FAIL_WARNINGS set.
Change paramCommsMgr to not use new

This prevents a threading problem where previously the new happened on
the wrong thread.
Change from qDebug to qWarning

This allows us to run with QT_FAIL_WARNINGS to find bugs. Also temp
comment out of failed signal connection.
Make sure timer start/stop happens on class thread
Fix override of QWidget update signal
Handle load failure correctly
Handle file open correctly

Path through code allowed for xmlfile to be used when file was not
opened. Also changed qWarning->qDebug to allow QT_FAIL_WARNINGS to be
used to find bugs.
Merge pull request #834 from DonLakeFlyer/ThreadingFixes

Threading fixes