When multiple threads share the Bind instance in a Document and do
lookup on the objects contained inside, that may trigger a new object
creation in some situations - which needs to be synchronized.

Link now caches imports. That means importing the same library (say, Qt)
from more than one file no longer creates an importing namespace for
each one. Instead, a single one is created for the instance of Link.

To make this work, the type environment in ScopeChain has been given its
own type: Interpreter::TypeEnvironment. That has the added benefit of
being able to carry meta-information about imports. You can use
TypeEnvironment::importInfo(qmlComponentName) to get information about
the import node that caused the import of the component.

We don't want people modifying the shared component chain on a
const Context *.

Now that Contexts are cached, it needs to be copyable. However, the
ScopeChain has a QmlComponentChain member that owns resources and didn't
have a correct copy constructor or copy assignment operator.

I've made QmlComponentChain non-copyable and store a shared pointer to
an instance instead, as it will generally not change for a given
context.

Reviewed-by: Lasse Holmstedt

* If possible, create LookupContexts through SemanticInfo; it caches the
  linked Context and will be faster.
* Contexts now own their Engine.

Reviewed-by: Lasse Holmstedt

In preparation for caching Contexts.

Reviewed-by: Erik Verbruggen

To make sure
property color foo: "white"
is of type color, not string.

Done-with: ckamm

Done-with: ckamm

Task-number: QTCREATORBUG-1757

Task-number: QTCREATORBUG-1737
Reviewed-by: Erik Verbruggen

When reading the xml file describing the Qml types, we incorrectly
classified all functions as methods. They should be slots, since
otherwise qmldump couldn't have dumped them in the first place.

Task-number: QTCREATORBUG-1755
Reviewed-by: Erik Verbruggen

By actually storing the documents instead of only the root and id
environments.

Filtering them out has long since become unnecessary. It was used back
when JS files were sourced from Script elements - there they'd only
make the functions available. Now functions and variables are imported.

Task-number: QTCREATORBUG-1735
Reviewed-by: Erik Verbruggen

The type information is now generated at runtime.

Done-with: owolff

Task-number: QTCREATORBUG-1021
Reviewed-by: Roberto Raggi

Such as
property int foo: bar
property int bar: foo.

Task-number: QTCREATORBUG-1389
Reviewed-by: Roberto Raggi

Reviewed-by: Roberto Raggi

Reviewed-by: Christian Kamm

* Context::build was potentially dangerous. Link and ScopeBuilder
  went out of scope before their results stopped being used.
* ScopeBuilder: If no function scope object was found, don't add it.

Reviewed-by: Erik Verbruggen

The documentation requires having it there.

50cc55af broke it.

Reviewed-by: ossi

Reviewed-by: Erik Verbruggen

Reviewed-by: Roberto Raggi

Done-with: Erik Verbruggen

At least direct recursion with name="Foo" extends="Foo" is detected
and rejected.

Done-with: Erik Verbruggen

Done-with: Erik Verbruggen

This used to contain all functions declared in Script blocks. With them
gone, there's no reason to keep it.

Use ScopeBuilder.push(...) for the same functionality.

Reviewed-by: Erik Verbruggen