Added "reason" parameter to deviceConfigurationChanged method, it will allow to react differently on user choices, autoconfigurer and configuration loading.
Merge branch 'master' of https://github.com/qreal/qreal into device-configuration-change-reasons
reasons system now fixes bug with world model disappearance
fixed desync with 2d model and docked sensors configuration widget
disabled 2d model when not on diagram tab, since changes to configuration or world model will not be saved anyway, which can be very confusing.
some cleanup
Merge pull request #1308 from qreal/device-configuration-change-reasons

Device configuration change reasons