Various ItemMeta fixes.

Fixes BUKKIT-3408, BUKKIT-3190, BUKKIT-3191, BUKKIT-3407

These changes relate mostly to semantical changes for serialization
contract, exception of changing the map scaling value from byte to boolean,
what it should have been in the first place. Appropriate unit tests were
added for CraftMapMeta, as they were missing.
Spigot for 1.4.6. This commit has undergone basic testing and appears to now be safe for careful production usage. Please report any bugs to IRC as soon as you encounter them. Long live Spigot!
Update Maven Shade Plugin to version 2.0. Fixes BUKKIT-3213
Address BUKKIT-3286 by firing the inventory close event when a secondary container is closed due to the player entity being destroyed. This covers all edge cases such as server stop / player kick / player quit.
Update item merge logic
Try old 1.4.5 dig speed algorithm for better results.
Add dependency-reduced-pom.xml to .gitignore
Try old 1.4.5 dig speed algorithm for better results. (reverse-merged from commit ea993ead2ff71074204f7cb5ad4b5ade4e0c88a2)
Include NibbleArray from mc-dev for diff visibility
Implement 'lightening' of NibbleArrays - only allocate buffers when non-trivial value
Saving from 40-45% of memory use by chunk section data.

Finish up NibbleArray lightening work - use for Snapshots, reduce copies

Fix nibble handling with NBT - arrays aren't copied by NBTByteArray
Return LOHS to full operation.
Update timeout time to new default value.