Kit: Introduce variables for Kit display names

This change also adds a AbstractMacroExpander for the QtKitInformation.

It supports the following variables in the Kit display name:

 %{Qt:version} - Qt version number
 %{Qt:type}    - Qt type
 %{Qt:name}    - Qt version name
 %{Qt:mkspec}  - mkspec used by the Qt version

Task-number: QTCREATORBUG-11118
Change-Id: I7263781336ab561c34880b187ebd55e81e6ca215
Reviewed-by: Daniel Teske <daniel.teske@digia.com>
Reviewed-by: hjk <hjk121@nokiamail.com>