kconfig: qt flavour makefile fixes

* Add comments to the makefile
* fix moc/uic invocation
* Compile moc classes as objects and link to qconf instead of including with #include.
  This is more compliant to the way IDEs like QtCreator work.
kconfig: qt flavour, add missing updateTree

* Remove all #includes for moc files
* Add ui option to show/hide subtrees of disabled options.
* Update the entire model on current item change like gconf