The special event filter probably shouldn't eat the enter key if we are
in the editing state.

Done-with: Thomas Hartmann

Reviewed-by: Roberto Raggi

Done-with: Thomas Hartmann

Add utils-lib.pri, along the lines of e.g. cplusplus-lib.pri

Reviewed-by: Alessandro Portale

Previously, the user had to navigate to the context of a qml item in
order to edit its source code in Live Preview mode. This change tells
the client to update when new objects are created on server-side, and
makes the editing possible without having to manually trigger updates.

When a change is done to an element that cannot be changed due to
debugger/qdeclarative limitations, a warning is shown to the user in QML
JS Editor.

Reviewed-by: Olivier Goffart

see 576642a7 for details

This one should be called when a component is changed and components
using it need to be reloaded.

isAvailable() returns true if a Quick ToolBar is available
for that node

The parameter force now forces the activation of the Quick
ToolBar even if it is not shown by default (enabled).

Also, update the gray mask that appears when user enters context of some
item. The mask is grown if the item changes its geometry, but never
shrunk, as this would introduce annoying flicker on the screen.