Plasma/conditionalQMLImports

Conditional imports

In order to restrict applications or components in general, a security mechanism is needed in Qt. The basic design should be the following:

• In the import code path, the import is either done right away (current case), or it uses an optional import policy agent, which checks if the application or component has sufficient privileges, and either allows or denies the import
• The policy agent is replacable, much like QNetworkAccessManager
• import performance in current case should not suffer

This obviously needs changes in Qt, and should be implemented in collaboration with upstream Qt.