Reviewed-by: Roberto Raggi

 * Expand environment arguments
 * Introduce new kind: ExistingCommand
 * Use PATH to look up ExistingCommand

Reviewed-by: dt

Add a method to find an executable:
 * Expand environment variables
 * If relative: Check provided directories
 * If still not found: Check the path

Reviewed-by: dt

It's meant to be.

Reviewed-by: Daniel Molkentin

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.

Fix capitalisation. Make tooltips more informative.

Reviewed-by: thartman

The Qt4ProjectManager now uses metacalls to inform the QmlJSModelManager
about the project data.

Done-with: hjk

Reviewed-by: dt

Task-Nr: QTCREATORBUG-2409

Reviewed by:  Thomas Hartmann

  Reviewed by: Kai Koehne

Task-Number: QTCREATORBUG-2406
Reviewed-by: hjk

Reviewed-By: Friedemann Kleint

Task-Number: QTCREATORBUG-2375
Reviewed-by: hjk

Task-Number: QTCREATORBUG-2375

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.

Introduce some more private classes for the coreplugin,
use header include convention
<QtModule/QClass>, de-qobjectify VariableManager.

To make it work with the HistoryCompleter.

Rename 'QML standalone application' to 'QML application'
and the 'old-style' QML applications to
'QML Viewer based applications'.

For the QML renaming:
Rubber-stamped-by: Alessandro Portale <alessandro.portale@nokia.com>

Task-Number: QTCREATORBUG-2118