Netty IO fixes
Fixes to Client

Move enterGame to Nifty event
Fix logger message
Fix function name
Handle fatal errors

Improve handling of Runtime errors thrown all the way up the stack.
Nifty accessor fixes
Basic model file support

Loading of model files
Basic model file structure
Initial player model file
Setup some more OpenGL environment conditions
Reworked registration screen UI

Reworked layout
Added button & functionality to return to login screen (fixes #16)
Fixed accessor visibility for Nifty.
More work on in-game

Removed sample quad, added calls to render player.
Implement logout due to disconnection
Lower logging level of character selection
Add sharable annotation to allow reconnection

Per Netty IO documentation, to allow reconnection attempts using the
same channel handler.
Implement logout handling in GameClient
Rework lobby, implement logout button
Add sharable annotation to Netty handler

Per Netty docs, required to indicate handler is shared between multiple
connection attempts in Netty 4.0
Make username and password optional for logout
Fix login handling in register state

Handle successful logins properly.
Possible fix for issue #61
Improve state transitions

Ensure the state is set correctly when screen switching.
Refactor client requested logout handling.

Use pre-existing logout method for valid logout.
Add new trace message
Refactor logout message handling to check for no existing logins.
Tweak import to clean up method
Refactor models package

Moving under client package.