"Lighthouse" integrated into main Qt codebase

Lighthouse is integrated!

Lighthouse, the project name for the Qt Platform Abstraction which aims to make porting Qt to new platforms easier, has been integrated into the main codebase for Qt (i.e. the master Git repository, rather than its own separate one) and will be part of the code released with Qt 4.8, although it will not necessarily be officially supported. Latest changes will still be published to the public Lighthouse repo, and merged to the master branch about weekly.