Introduction of Alchemy skill!

New skill: Alchemy (Based on EasyMFnE's former standalone custom Alchemy skill plugin)

Alchemy has two abilities: Catalysis and Concoctions.
Catalysis speeds up the brewing process.  (by default, unlocks at lvl 100 with max speed of 4x at lvl 1000)
Concoctions allows brewing of more potions with custom ingredients (e.g. Ink Sac for Potion of Blindness)
Concoctions has 8 configurable ranks of ingredients.

Custom potion tree is defined in potions.yml
Vanilla brewing tree is represented there, as well as many new potions utilizing the various status effects not currently attainable in potion form.  Each potion can be given a custom display name and lore, if desired, otherwise it is named after its primary effect and given no lore.