[lazarus] More Notebooks now in CVS

[Curtis White]

I just created a new TCustomNotebook component in extctrls.pp and
customnotebook.inc.  I changed TNotebook and the new TTabbedNotebook (in
tabnotbk.pp) to both inherit from TCustomNotebook.  So now TNotebook acts like
a Dellphi TNotebook and the TTabbedNotebook works like the same component in
Delphi. 

I also fixed the notebook example to show both the TNotebook and the
TTabbedNotebook components.

I have committed all this to CVS.

For some reason, these components write out a bunch of gtk errors to the
console. I don't know where these are coming from. Can someone take a look at
it and see if you can see where these are coming from?  Apparently I have been
looking at my code for too long and cannot find the problem.


Curtis