[fpc-pascal] A patched unit overriding the default - like Delphi supports

[Marco van de Voort]

In our previous episode, Graeme Geldenhuys said:
> > If only the unit implementation changes, and you don't use inlines and
> > you compile the unit with the same compiler flags, can this ppu be used
> > instead of the original?
> 
> So far so good.  I managed to successfully replace ibconnection.pas which
> is part of the fcl-db code.

Of a snapshot or of a release?