[crossfire] Balm of return home

[Nicolas Weeger (Laposte)]

Hello.

Currently, balms of protection and such work correctly even on unholy grounds.
On the other hand, balm of return home (word of recall) doesn't work. This 
because when it actually executes it checks again whether ground is holy or 
not, thus it can fail.

I think we could make its behaviour coherent with other balms, and enable balm 
of return home to work even on holy ground. It would even make sense again to 
actually use alchemy to create some :)

My proposed fix is to set the DM_FLAG to the word of recall's spell effect (in 
cast_word_of_recall), and check that in the execute_word_of_recall function. 
To do that, I'd say to just set that flag on the balm itself (since the balm 
merely contains the spell).

Opinions, comments and criticism welcome :)

Nicolas