[Lazarus] DockSite example updated

[Hans-Peter Diettrich]

The second last update adds virtualization to the DockSite example. In 
uMakeSite you find an TMasterSite component, that allows to add elastic 
docksites and docking capability to any form. These methods shall allow 
to make the IDE dockable, with minimal impact on the existing IDE forms.

In the last round the application layout shall become persistent.

DoDi