Add missing gen2 items

There are some berries and items that were lacking for gen2.  According to UPC the Berserk Gene's confusion lasts 256 turns.  It lasts the normal duration currently.
Removing redundant berries

The status curing berries can be implemented using aliases to the existing berries.
Remove Berry

Berry is exactly the same as Oran Berry
Remove Gold Berry

According to Slayer95 gold berry behaves identically to ADV sitrus berry.
Allow gen2 berries to be used
Allow Lum Berry in gen 2
Change gulpfile to take advantage of gulp APIs

Gulp's `gulp.src` can also take an [array of globs](https://github.com/gulpjs/gulp/blob/master/docs/API.md), which makes iterating through all the directories manually rather redundant.
Merge pull request #828 from ToucheSir/patch-1

Change gulpfile to take advantage of gulp APIs
Gen 4: Fix Beat Up
NEXT: Mega Gengar no longer levitates
Update README.md

Changes:
Removed Shuckle getting Leech Seed as it doesn't.
Updated numbers on Explosion/Self-Destruct to current values.
-Crestfall
Merge pull request #829 from CrestfallPS/patch-2

Update of GenNEXT README
Allow Charizard Y and Mewtwonite Y in randoms

For Pokemon with multiple mega evolutions (Charizard and Mewtwo) it should randomly select either.
Remove typo
Merge pull request #830 from Relados/patch-58

Allow Charizardite Y and Mewtwonite Y in randoms
Merge pull request #688 from Relados/patch-12

Add missing gen2 items
Add methods to get effective Item or Ability
pokemon.hasItem and pokemon.hasAbility account for Gastro Acid, Klutz, Magic Room and Embargo
Fix ignoring abilities or items sometimes being not effective
Items: Light Clay, Metronome
Abilities: Aura Break, Contrary, Gluttony, Levitate, Mega Launcher, Minus, Mold Breaker, Persistent, Plus, Shadow Tag, Slow Start, Soundproof, Stall, Unburden, Teravolt, Turboblaze, Zen Mode
Fix 2-turn moves ignoring No Guard
Merge pull request #832 from Slayer95/master

Fixes for Embargo, Gastro Acid, Klutz, Magic Room and No Guard