With this patch, when calling 'setFocus()' on a QNitpickerViewWidget, the
Nitpicker view gets the input focus (provided that the parent Qt window
already had it).
Fixes#1314
The QPluginWidget used to be a QNitpickerViewWidget but the new loader
interface does no longer hand out a view capability. So we need to
decouple both classes. This patch moves the view-geometry calculation to
a separate class to make it easier reusable, in particular for the
QPluginWidget.
This patch changes nitpicker's session interface to use session-local
view handles instead of view capabilities. This enables the batching
of multiple view operations into one atomic update.
This patch changes the top-level directory layout as a preparatory
step for improving the tools for managing 3rd-party source codes.
The rationale is described in the issue referenced below.
Issue #1082
