This happened if the file is openned after the debugger has started

This should speed up the matching between the AST nodes and the debugIds

 * Fix all warnings about non-explicit constructors except for those
   in 3rdparty code.

It was not very useful without being able to e.g. move things around.

Animation play/pause buttons are now merged on observer toolbar. Also, a
bugfix to inspector toolbar.

There is now a hook in QDeclarative itself for that.
Needs commit af2b28f9ca07057 of Qt

Reviewed-by: hjk

Creating LookupContext seems to be expensive, so don't update anything
unless debug mode is already running.

Easier to use now by just clicking on one button, and takes less space.

A new debugger engine, QmlCppEngine, is introduced, which wraps gdb
and qml engines into one. Alternatively, if using Windows, Cdb is used
instead of Gdb.

Most of the debugger ui switcher is now rewritten, and it is tailored
for the QML and CPP layout case, the only one supported anyway.

Reviewed-by: hjk

The problem was that we did not query the object with the good engine id

+ add missing tr()

Now, QmlEngine creates the connection to the inferior (debuggee), and
notifies QmlInspector when a connection is established. Before,
inspector created the debugger engin, which was wrong.

QmlEngine's responsibilities are connecting to the debuggee and basic
QML/JS debugging features like locals & watchers, breakpoints etc.
QmlInspector takes care of Live Preview and other fancy inspection
features.

Reviewed-by: hjk

For starters, we only remember whether the initial warning about dangers
of Live Preview was shown.

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

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

If an object is created at the same location of another old object,
It could be matched.