QmlDesigner.PropertyEditor: remove remaining transactions from controls

Since there are issues with transaction we play safe.

Task-number: QTCREATORBUG-11134

Change-Id: I2144f81f14046317d967d6644befeb74e8d27eb8
Reviewed-by: Marco Bubke <marco.bubke@digia.com>
QmlProjectManager: Fix support for Files

Change-Id: I7b6931eb193aca446bc7936f003c5a2f5e41c7f6
Reviewed-by: Christian Stenger <christian.stenger@digia.com>