Organized methods in GlowServer.
Tidied and implemented parts of GlowWorld, minor GlowServer implementation fixes.
Tidied GlowBlock and GlowEntity and implemented metadata methods.
Minor cleanup in GlowChunk, GlowBlockState, and GlowLivingEntity.
Update README.md

Signed-off-by: Steven Downer <grinch@outlook.com>