#22 Add conditional (tax) commands

[Maurits van Rees]

If the tax command is set in the player config file,
all planets are taxed. There is also the option to mark
planets with 't' for taxation when the general tax
command is not given.

How about the following, in analog to the phost
alliance command:
+t: always tax this planet (like t would do now)
~t: only tax this planet when the tax command is given
-t: never tax this planet, even when the tax command is
given.

The same could be done for other actions perhaps in the
future.

Now that I write this I wonder if I mentioned this
before. Well, I don't see it in the Feature Request
list, so it's fine to put it here.

Reinout, you started on a randgen like thing once. Is
there any code that can be put online or emailed to me?