Return correct hasLineOfSight value for players. Fixes BUKKIT-4634

Prior to this change when a plugin called Player.hasLineOfSite() the
method would always return false because EntityHuman does not extend
EntityInsentient. This commit changes that by explicitly checking for
line of sight between two entities and returning that value.
Add source encoding to the maven compiler plugin.

This change adds the source encoding to the maven compiler plugin, which
will strictly enforce build consistency on multiple platforms and address
possible compilation issues on some of the source files. The source
encoding unintuitively is system-specified by default.
Set current recipe to null when a recipe isn't found. Fixes BUKKIT-2311

This commit restores the diff from 84dbc21aa71b96fd1d2ea40d624b536309118cde
that has since been lost.
Fix improperly initialized usernames
Check that a vehicle is a Vehicle before casting. Fixes BUKKIT-4749

When an entity is being moved as the passenger of an entity from one
entity to another, a VehicleExitEvent is fired, but it is assumed that the
current entity is a Vehicle. However, entities can be passengers of more than
just Vehicles, which causes a ClassCastException to be thrown.

This commit fixes the issue by checking that the current entity's vehicle's
bukkitEntity is an instance of Vehicle before casting it to Vehicle.
Properly set persistence flag for bred animals. Fixes BUKKIT-4751
Correct location of fire from lightning strikes. Fixes BUKKIT-4707

Previously fires spawned by lightning strikes were in the wrong locations.
This introduced the possibility of having blocks replaced when they should
not be.

EntityLightning now uses the correct locations as defined to spawn the
fires when needed.
Update and add new sound mappings. Fixes BUKKIT-4756
Add support for custom Hopper inventories. Fixes BUKKIT-4722

Opening a hopper inventory created by Server.createInventory will
currently have no effect as proper handling code is missing in
CraftEntityHuman for hopper inventories that aren't associated with a tile
entity or minecart. Initialization logic for hoppers is also missing from
CraftContainer, which is necessary for the opening of custom hopper
inventories.

This commit fixes the two aforementioned by adding proper handling to
CraftHumanEntity for opening inventories not associated with a tile
entity, and by adding initialization logic for hoppers to CraftContainer.
Provide a tab completion handler for JLine. Adds BUKKIT-4168
Remove unnecessary error logging. Fixes BUKKIT-4406
Use correct spawn reason for Zombie reinforcements. Fixes BUKKIT-4744
Add missing villager sounds. Addresses BUKKIT-4756
Fix villager death sound
Update for 1.6.2_01 renames.
Updated version to 1.6.2-R1.0 in pom.xml for RB.
Updated version to 1.6.2-R1.1-SNAPSHOT for development towards next release.