[Lazarus] Property TComponent.Tag change

[Michael Van Canneyt]

Hi,

To remain compatible with the upcoming Delphi 64-bit release, I've changed
the 'Tag' property type from Integer -> PtrInt.

The practical upshot from this is that you can store a pointer in it on all platforms.
(a widespread abuse of the Tag property).

This potentially breaks some existing code if you rely on Tag having a size of 4 bytes.

If you do not rely on this, it should not break any code. If it does, I'd be interested
in hearing about it so we can provide workarounds on the website.

Michael.