[Lazarus] New NumbersOnly property for TCustomEdit (r43678)

[Bart]

Hi,

I have implemented a NumbersOnly property for TCustomEdit in r43678.
Currently it only does something on Win32/Win64 and WinCE (the latter
one I am unable to test), since these widgetsets have native support
for this feature.

It is only available in trunk, and I don't think it'll be in 1.2
release (since it's a new feature sice we released 1.2RC1).
ATM it is only published for TEdit (for all other descendants it's public).

I don't know if GTK2, Carbon, Cocoa and QT can support this.

Please test and report bugs in the bugtracker.

Bart