No longer deploy image files and sources of QML imports.

These files can be omitted for the Qt Quick Controls and
Qt Quick Dialogs modules.

Task-number: QTBUG-28766
Task-number: QTBUG-31565
Change-Id: Id02939a7124cd5db83d81dcc59663ddf4d091f70
Reviewed-by: Kai Koehne <kai.koehne@digia.com>