Changes of spell sounds.

Replaced or added sound effects of some spells: Lower armor — replaced
SND_SPELL_ARMOR_START with SND_SPELL_LOWER_ARMOR, Speed — replaced
SND_SPELL_INVISIBILITY_END with SND_SPELL_SPEED_END , Protection from
fire — added SND_SPELL_FIRE_PROTECTION_LOOP and
SND_SPELL_FIRE_PROTECTION_END, Trap (Rune of guarding) — replaced
SND_SPELL_FIRE_HIT with SND_SPELL_RUNE_OF_GUARDING_END, Ice field —
added SND_SPELL_ICE_FIELD_LOOP and SND_SPELL_ICE_FIELD_END, Incinerate
and Mass Incinerate — replaced SND_FIREPLACE with
SND_SPELL_INCINERATE_LOOP and added SND_SPELL_INCINERATE_END.