QtIFW

Introduce InstallAction property for component

Fixes calculation of component size inside
maintenance tool. Don't manipulate check state
of components while calculating dependencies.
Prepare feature: live preview of dependencies.

Change-Id: I0485df8383bc9149a996456e09878fc5676bb27b
Reviewed-by: Kai Koehne <kai.koehne@theqtcompany.com>