Buff deep elf knights (new spell sets, more damage)

Once more, a reaver with a mess of spells is cleaned up a little,
though this time multiple spellsets are definitely kept. The deep
elf knight was little more than a stronger deep elf fighter, which
is already a differently-equipped differently-placed orc wizard.
To emphasize the vague melee prowess suggested by the name "knight",
they get a 1.5x base damage boost from 14 to 21, making them not weaker
than orc warriors. They're also getting new spell sets, with a mix
of conjurations and self-buffs. The original three spellsets they had
were directly from orc wizards:
1. Magic Dart, Slow, Haste, Blink
2. Throw Flame, Invisibility, Magic Dart, Confuse
3. Throw Frost, Cantrip, Haste, Throw Flame, Magic Dart, Invisibility
Their new spellsets, emphasizing some sparsely-used spells and a bit
more sheer strength:
1. Dazzling Spray, Conjure Flame, Invisibility, Swiftness
2. Throw Icicle, Haste, Invisibility, Condensation Shield
3. Stone Arrow, Iskenderun's Mystic Blast, Haste, Shroud of Golubria

Nearly all of the placements of deep elf knights have been left
untouched; its use as a strong mid-tier elf should make more sense
now. The only exception is possibly the earliest one, in one of the
baileys: there, the equipment has been deliberately held back to
essentially nerf its use there.