[crossfire] New feature for scrolls and spellbooks

[Nicolas Weeger (Laposte)]

> Just implemented the feature request: add blessings and curses to scrolls
> More details here:
> https://sourceforge.net/tracker/index.php?func=detail&aid=656191&group_id=1
>3833&atid=363833

Forgot to tell: as part of that implementation, i changed the behaviour for 
scroll/spellbook reading failure.
The behaviour was inconsistent, in the sense that if "spell failure effects" 
was turned off in configuration, some failures did mana draon, others, 
because too powerful (mana storm, confusion, paralyse), didn't do anything.
I changed the behaviour so that at least mana drain occurs - seems more 
coherent that way.


Nicoals