Add form difference prose for Kalos Pokémon.

To do:

- Add form prose for Mega Evolutions
- Update old Pokémon's form prose
- Nail down the style a little:
    * Do I want to capitalize the form moniker?  e.g. "Vivillon's
      Pattern depends..." or "Trading [...] does not affect the Pattern
      it will have..."
    * What about when I'm actually writing a form name?  e.g. "The Fancy
      and Poké Ball Patterns..."  (This is what I do at the moment.)
    * Change all remaining instances of "Forms only affect appearance"
      to "Forms only differ in appearance".  It sounds better and fits
      with the other opening sentences better.

pokedex/data/csv/pokemon_species_prose.csv

@@ -58,3 +58,19 @@ The Reveal Glass may be obtained by taking a Therian Landorus to []{location:abu
 647,9,"Forms only affect appearance.  In Black and White Versions 2, Keldeo becomes Resolute Form when it learns []{move:secret-sword} and reverts to Ordinary Form if it forgets that move."
 648,9,"Forms have different stats and types.  Meloetta changes form upon using []{move:relic-song} in battle, and reverts to Aria Forme outside of battle."
 649,9,Form changes to match Genesect's held Drive.  The only differences are the color of its weapon and []{move:techno-blast}'s type.
+666,9,"Forms only differ in appearance.  Vivillon's pattern depends on the real-world geographical region set in its original trainer's 3DS, and cannot be changed.
+
+Trading a Scatterbug, Spewpa, or egg does not affect the pattern it will have as a Vivillon.  Changing the 3DS's region setting will not affect the game's Vivillon pattern until the player starts a new game.
+
+The Fancy and Poké Ball Patterns do not correspond to any region and are only available through distributions."
+669,9,"Forms only differ in appearance.  Flabébé's flower is set when it is encountered, and cannot be changed."
+670,9,"Floette's five regular forms only differ in appearance.  Floette's flower is set when it is encountered, or as a Flabébé, and cannot be changed.
+
+Eternal Floette has higher stats, cannot evolve or breed, and learns []{move:light-of-ruin} at level 50.  It is currently not obtainable."
+671,9,"Forms only differ in appearance.  Florges's flower is set as a Flabébé or Floette, and cannot be changed."
+676,9,"Forms only differ in appearance.  Furfrou's trim can be changed at any time in Friseur Furfrou in Lumiose City.  It reverts to its Natural Form after five days unless trimmed again, or if it is deposited in the PC."
+678,9,"Male and female Meowstic have different level-up moves and hidden abilities.  While gender differences are not usually considered to be separate forms, Meowstic's are treated as such for practical purposes."
+681,9,"Forms have different stats.  If Aegislash's ability is []{ability:stance-change}, it changes to Blade Forme before using a damaging move, and reverts to Shield Forme before using King's Shield or upon leaving the field."
+710,9,"Forms have different stats.  Pumpkaboo's size is set when it is encountered, and cannot be changed."
+711,9,"Forms have different stats.  Gourgeist's size is set as a Pumpkaboo, and cannot be changed."
+716,9,"Forms only differ in appearance.  Xerneas is always in Neutral Mode outside of battle, and Active Mode in battle."