lock emiting signals while reading roleProperty from file
This resolves #292 (closed).
At opening the project BA reads properties and their roles from the project file, one by one.
After reading each value and its role BA puts them to the corresponding sessionItem
.
But at this procedure sessionItem
emits the dataChanged
signal that causes some chain of actions.
These actions can't be done correctly, because not all data are read from the project file to the moment.
The solution is to temporary prevent emitting signals while reading sessionItems.