Squish: Do not crash on fail in getEditorForFileSuffix()

Change-Id: I3d3519e2bb203e52afd2785aac46997616b4ca4b
Reviewed-by: Robert Loehning <robert.loehning@digia.com>
IWizard and derived classes: Code cleanups

There should be no functional changes, just removal of unnecessary
code. This includes:

* Removal of unused QObject *parent = 0 parameters to constructors
* Removal of unnecessary explicits
* Removal of unnecessary virtuals
* Removal of unnecessary constructors/destructors

Some explicits were added though where those were missing.

Change-Id: Iab570349ea950dad0a2d01af17bc6175f70832f1
Reviewed-by: Eike Ziller <eike.ziller@digia.com>
IWizard and derived classses: Fix WS issues

No change otherwise.

Change-Id: If23c9d56e48e9878c8424fc5863b70e9e4ff12f8
Reviewed-by: Eike Ziller <eike.ziller@digia.com>