Implement strict mode for qmldir modules

Implement strict mode for qmldir modules

Allow a module's qmldir to contain a module directive, which when
present specifies 'strict mode' import processing.  In strict mode,
type registrations are only permitted into the namespace identified
in the qmldir file's module directive.  In addition, any type
registrations to that namespace originating from other modules are
treated as error conditions.

Task-number: QTBUG-26551

Change-Id: I081bde2d3b83d3f28524440177fb2cd1ccee34ad
Reviewed-by: Chris Adams <christopher.adams@nokia.com>
Reviewed-by: Roberto Raggi <roberto.raggi@nokia.com>