IVE: Add user warning/error reporting for file loading

Warnings during file load should be presented to the user. And shown in the QtCreator panel.

• In the shared library add a reporting singleton class
  • The real implementation is set in the main application or in the QtCreator plugin
• Add methods to report warnings and errors
• Implement the warning reporting dialog/panel in the main window
• Implement the warning reporting for QtCreator