[Lazarus] New NumbersOnly property for TCustomEdit (r43678)

[Marco van de Voort]

On Mon, Jan 13, 2014 at 07:58:02PM +0000, Graeme Geldenhuys wrote:
> 
> The Free Pascal team wants Delphi compatibility in both directions.
> Moving from Delphi to FPC, and then still keep the ability to move back
> to Delphi. The second part is ridiculous as far as I'm concerned - it
> limits FPC too much in what it can do, change or improve.

It should be possible to maintain components for both Delphi and FPC at the
same time yes, with minimization of ifdefs.

The trouble is that anything else is a lot more difficult than most people
think.

Both making _meaningful_ extensions and having them not compromise that
compatibility in a practical way.

Exceptions that require codechanges pile on over time, making the
question of compatibility academical.