[Lazarus] Docking manager implementation

[Hans-Peter Diettrich]

Mattias Gaertner schrieb:

>> Java has layout managers, and the "modern" widgetsets also have
>> layout managers, which might be usable even with Lazarus.
> 
> How?
> The LCL needs an widgetset independent layout manager.

Right. But since we have to define an interface, we could look at 
existing layout manager models. Perhaps we can use some of the widgetset 
managers without much extra coding? Also Lazarus ports of such managers 
will be easier, when existing managers will not deserve much modifications.

DoDi