Add Utility Classes

Provides Utility classes for Spigot and plugins to use.

EvictingQueue: Backport of Guava v15 Class.
JSONUtil: Provides utility methods for building json-simple documents.
LoadingMap: Create a map with an auto loader to auto load on .get() if missing, similar to a LoadingCache.
MRUMapCache: Caches most recently used key/value for faster lookups on on 1 or 2 key maps.
Timings v2

Massive improvement of the Spigot Timings system.
Fixes many bugs, increases identification accuracy, adds more reporting data.
Changes output format to be XML and includes a ton of information about the
servers performance over time so that the web view can display much more about
the servers performance.

Adds new API Bukkit.spigot().getBukkitConfig(),
Renames Bukkit.spigot().getConfig() to getSpigotConfig()
Adds new API Player.spigot().getPing() API
Adds new API Timings.of(Plugin, String) API for plugins to add their own timings.
Adds many other new Timings API for controlling Timings settings and generating reports.