Added ender portal support (see #325).

Adds awardAchievement variant which only awards the achievement if its
parent has already been awarded. Fixes some desyncs with world switching.
Implemented basic damage functionality, including drowning.
Fixed color wrapping by converting flat messages to json.
Fixed not being able to place blocks inside snow.
Completely obliterate rogue threads on exit (fixes #179).

The shutdown monitor thread is now more thorough about killing the threads
it finds, and will still terminate even if a thread could not be killed.
Added 1.8 crafing recipes (see #314).

4x red sand -> 1x red sandstone
4x red sandstone -> 4x smooth red sandstone
2x red sandstone slab -> 1x chiseled red sandstone
2x stone bricks slab -> 1x chiseled stone bricks
2x cobblestone, 2x quartz -> 2x diorite
4x diorite -> 4x polished diorite
4x granite -> 4x polished granite
4x andesite -> 4x polished andesite
2x dirt, 2x gravel -> 4x coarse dirt
3x red sandstone -> 6x red sandstone slab
bunch of things -> rabbit stew
4x rabbit hide -> 1x leather
4x oak plank, 2x stick -> 3x oak fence
fences: spruce, birch, jungle, acacia, dark oak
2x oak plank, 4x stick -> 1x oak fence gate
fence gates: spruce, birch, jungle, acacia, dark oak
doors: oak, spruce, birch, jungle, acacia, dark oak
6x iron ingot -> 3x iron door
4x iron ingot -> 1x iron trap door
7x stick, 1x stone slab -> 1x armor stand
6x red sandstone -> 4x red sandstone stairs
1x stone brick, 1x vine -> 1x mossy stone brick
1x cobblestone, 1x vine -> 1x mossy cobblestone
1x diorite, 1x quartz -> 1x granite
1x diorite, 1x cobblestone -> 1x andesite
9x slime ball -> 1x slime block
1x slime block -> 9x slime ball
furnace: stone brick -> cracked stone brick
4x prismarine shard -> prismarine
9x prismarine shard -> prismarine brick
8x prismarine shard, 1x ink sac -> dark prismarine
5x prismarine crystals, 4x prismarine shard -> 1x sea lantern
furnace: rabbit -> cooked rabbit
Added RedundantModifier checkstyle rule.
Implemented buckets.
Implemented basic farming support.

Added placement and interact handling for hoes, wheat, melons, pumpkins,
nether warts, carrots, potatoes, and cocoa beans. No growth ticking yet.
Added a blank 'server.ip' key to the default glowstone.yml.
Call PlayerMoveEvent.

Based partially on the code of @JeromSar. The event is called more often
than CraftBukkit due to the lack of movement buffering.
Added huge mushroom and more tree generation.

Includes a better generic tree system based on oak, small jungle, and
cocoa trees, as well as birch, tall birch, and spruce tree generation.
Now fires StructureGrowEvent during tree generation.
Added script that fetches Glowkit PRs for Travis.

For PRs, the PR body will be looked up and scanned for links to Glowkit
PRS, which will then be included in the build. Also reorganizes the Travis
script slightly.
Fixed PlayerMoveEvent handling and teleportation offset.

When PlayerMoveEvent's destination is changed, it should be considered a
teleport and fire the appropriate event and handle world changes.

PositionRotationMessage now refers to the client's feet instead of eyes.
Added placement and interact handling for fence gates and trapdoors.
Fixed ShapedRecipe matching (fixes #465).
Fixed hoe interaction with coarse dirt and podzol.
Fire PlayerItemHeldEvent when players switch their held item.
Implemented remote console (rcon) support (closes #451).
Added support for player and mob heads.

Includes dandling for the skull item, block, and tile entity, as well as
lookup of profiles based on username for Bukkit support.