[fpc-pascal] Threading support under FPC

[Marco van de Voort]

> How good is the threading support in Free Pascal?  I'm using 2.1.1.  I
> haven't used threading before under FPC and am about to revamp an
> in-house application to support mutliple threads.  I don't want to
> start the app and then find out that there is some major stability
> issues with threading support.  Anybody find issues with FPC's
> threading support?  Any special params that I need to pass to the
> compiler?

- On *nix import cthreads as first unit of your project/mainprogram.
- Indy doesn't work on some platforms, notably FreeBSD.  Linux and Windows
	seem to work. OS X unknown.
- Threadvar's are initialised to the value of the mother program. This
	can be dangerous for e.g. filevariables. (?)