iwd2::cg: learn priest spells earlier, with other spells
iwd2::cg: remove commented code and unnedeed import

after second though, it's useless to keep around, levelup will require
further mods
iwd2::cg: display known spells in the overview
GetMageSpells: magesch.2da has -1 as default, so make sure we don't get it

fixes sorcerers not being able to pick any spells
RemoveKnownSpells: iwd2 compatibility
iwd2::cg: remove all the usual known spell types before learning spells

fixes going back and forth leaving previous learning intact, eg. bards
with extra known druid spells